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 #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       || (__libc_enable_secure
  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 (strcmp (*name, _nl_C_name) == 0 || strcmp (*name, _nl_POSIX_name) == 0)
  75     {
  76       /* We need not load anything.  The needed data is contained in
  77          the library itself.  */
  78       *name = (char *) _nl_C_name;
  79       return _nl_C[category];
  80     }
  81
  82   /* We really have to load some data.  First see whether the name is
  83      an alias.  Please note that this makes it impossible to have "C"
  84      or "POSIX" as aliases.  */
  85   loc_name = (char *) _nl_expand_alias (*name);
  86   if (loc_name == NULL)
  87     /* It is no alias.  */
  88     loc_name = (char *) *name;
  89
  90   /* Make a writable copy of the locale name.  */
  91   loc_name = __strdup (loc_name);
  92
  93   /* LOCALE can consist of up to four recognized parts for the XPG syntax:
  94
  95                 language[_territory[.codeset]][@modifier]
  96
  97      and six parts for the CEN syntax:
  98
  99         language[_territory][+audience][+special][,[sponsor][_revision]]
 100
 101      Beside the first all of them are allowed to be missing.  If the
 102      full specified locale is not found, the less specific one are
 103      looked for.  The various part will be stripped of according to
 104      the following order:
 105                 (1) revision
 106                 (2) sponsor
 107                 (3) special
 108                 (4) codeset
 109                 (5) normalized codeset
 110                 (6) territory
 111                 (7) audience/modifier
 112    */
 113   mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
 114                            &codeset, &normalized_codeset, &special,
 115                            &sponsor, &revision);
 116
 117   /* If exactly this locale was already asked for we have an entry with
 118      the complete name.  */
 119   locale_file = _nl_make_l10nflist (&locale_file_list[category],
 120                                     locale_path, locale_path_len, mask,
 121                                     language, territory, codeset,
 122                                     normalized_codeset, modifier, special,
 123                                     sponsor, revision,
 124                                     _nl_category_names[category], 0);
 125
 126   if (locale_file == NULL)
 127     {
 128       /* Find status record for addressed locale file.  We have to search
 129          through all directories in the locale path.  */
 130       locale_file = _nl_make_l10nflist (&locale_file_list[category],
 131                                         locale_path, locale_path_len, mask,
 132                                         language, territory, codeset,
 133                                         normalized_codeset, modifier, special,
 134                                         sponsor, revision,
 135                                         _nl_category_names[category], 1);
 136       if (locale_file == NULL)
 137         /* This means we are out of core.  */
 138         return NULL;
 139     }
 140   else
 141     /* If the addressed locale is already available it should be
 142        freed.  If we would not do this switching back and force
 143        between two locales would slowly eat up all memory.  */
 144     free ((void *) loc_name);
 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
 165   if (locale_file == NULL)
 166     return NULL;
 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   /* Increment the usage count.  */
 185   if (((struct locale_data *) locale_file->data)->usage_count
 186       < MAX_USAGE_COUNT)
 187     ++((struct locale_data *) locale_file->data)->usage_count;
 188
 189   return (struct locale_data *) locale_file->data;
 190 }
 191
 192
 193 /* Calling this function assumes the lock for handling global locale data
 194    is acquired.  */
 195 void
 196 _nl_remove_locale (int locale, struct locale_data *data)
 197 {
 198   if (--data->usage_count == 0)
 199     {
 200       /* First search the entry in the list of loaded files.  */
 201       struct loaded_l10nfile *ptr = locale_file_list[locale];
 202
 203       /* Search for the entry.  It must be in the list.  Otherwise it
 204          is a bug and we crash badly.  */
 205       while ((struct locale_data *) ptr->data != data)
 206         ptr = ptr->next;
 207
 208       /* Mark the data as not available anymore.  So when the data has
 209          to be used again it is reloaded.  */
 210       ptr->decided = 0;
 211       ptr->data = NULL;
 212
 213       /* Free the name.  */
 214       free ((char *) data->name);
 215
 216 #ifdef _POSIX_MAPPED_FILES
 217       /* Really delete the data.  First delete the real data.  */
 218       if (data->mmaped)
 219         {
 220           /* Try to unmap the area.  If this fails we mark the area as
 221              permanent.  */
 222           if (__munmap ((caddr_t) data->filedata, data->filesize) != 0)
 223             {
 224               data->usage_count = UNDELETABLE;
 225               return;
 226             }
 227         }
 228       else
 229 #endif  /* _POSIX_MAPPED_FILES */
 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 locale;
 242
 243   for (locale = 0; locale < LC_ALL; ++locale)
 244     {
 245       struct loaded_l10nfile *runp = locale_file_list[locale];
 246
 247       while (runp != NULL)
 248         {
 249           struct loaded_l10nfile *here = runp;
 250           struct locale_data *data = (struct locale_data *) runp->data;
 251
 252           if (data != NULL && data->usage_count != UNDELETABLE)
 253             _nl_unload_locale (data);
 254           runp = runp->next;
 255           free (here);
 256         }
 257     }
 258 }
 259 text_set_element (__libc_subfreeres, free_mem);