locale/findlocale.c

   1 /* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 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   if (locale_file->decided == 0)
 145     _nl_load_locale (locale_file, category);
 146
 147   if (locale_file->data == NULL)
 148     {
 149       int cnt;
 150       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 151         {
 152           if (locale_file->successor[cnt]->decided == 0)
 153             _nl_load_locale (locale_file->successor[cnt], category);
 154           if (locale_file->successor[cnt]->data != NULL)
 155             break;
 156         }
 157       /* Move the entry we found (or NULL) to the first place of
 158          successors.  */
 159       locale_file->successor[0] = locale_file->successor[cnt];
 160       locale_file = locale_file->successor[cnt];
 161     }
 162
 163   if (locale_file == NULL)
 164     return NULL;
 165
 166   /* Determine the locale name for which loading succeeded.  This
 167      information comes from the file name.  The form is
 168      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 169   if (((struct locale_data *) locale_file->data)->name == NULL)
 170     {
 171       char *cp, *endp;
 172
 173       endp = strrchr (locale_file->filename, '/');
 174       cp = endp - 1;
 175       while (cp[-1] != '/')
 176         --cp;
 177       ((struct locale_data *) locale_file->data)->name = __strndup (cp,
 178                                                                     endp - cp);
 179     }
 180   *name = (char *) ((struct locale_data *) locale_file->data)->name;
 181
 182   /* Increment the usage count.  */
 183   if (((struct locale_data *) locale_file->data)->usage_count
 184       < MAX_USAGE_COUNT)
 185     ++((struct locale_data *) locale_file->data)->usage_count;
 186
 187   return (struct locale_data *) locale_file->data;
 188 }
 189
 190
 191 /* Calling this function assumes the lock for handling global locale data
 192    is acquired.  */
 193 void
 194 _nl_remove_locale (int locale, struct locale_data *data)
 195 {
 196   if (--data->usage_count == 0)
 197     {
 198       /* First search the entry in the list of loaded files.  */
 199       struct loaded_l10nfile *ptr = locale_file_list[locale];
 200
 201       /* Search for the entry.  It must be in the list.  Otherwise it
 202          is a bug and we crash badly.  */
 203       while ((struct locale_data *) ptr->data != data)
 204         ptr = ptr->next;
 205
 206       /* Mark the data as not available anymore.  So when the data has
 207          to be used again it is reloaded.  */
 208       ptr->decided = 0;
 209       ptr->data = NULL;
 210
 211       /* Free the name.  */
 212       free ((char *) data->name);
 213
 214       /* Really delete the data.  First delete the real data.  */
 215       if (data->mmaped)
 216         {
 217           /* Try to unmap the area.  If this fails we mark the area as
 218              permanent.  */
 219           if (__munmap ((caddr_t) data->filedata, data->filesize) != 0)
 220             {
 221               data->usage_count = UNDELETABLE;
 222               return;
 223             }
 224         }
 225       else
 226         /* The memory was malloced.  */
 227         free ((void *) data->filedata);
 228
 229       /* Now free the structure itself.  */
 230       free (data);
 231     }
 232 }
 233
 234 static void __attribute__ ((unused))
 235 free_mem (void)
 236 {
 237   int locale;
 238
 239   for (locale = 0; locale < LC_ALL; ++locale)
 240     {
 241       struct loaded_l10nfile *runp = locale_file_list[locale];
 242
 243       while (runp != NULL)
 244         {
 245           struct loaded_l10nfile *here = runp;
 246           struct locale_data *data = (struct locale_data *) runp->data;
 247
 248           if (data != NULL && data->usage_count != UNDELETABLE)
 249             _nl_unload_locale (data);
 250           runp = runp->next;
 251           free (here);
 252         }
 253     }
 254 }
 255 text_set_element (__libc_subfreeres, free_mem);