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       || (__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 = strdupa (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], NULL, 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], NULL, 1);
 136       if (locale_file == NULL)
 137         /* This means we are out of core.  */
 138         return NULL;
 139     }
 140
 141   /* The space for normalized_codeset is dynamically allocated.  Free it.  */
 142   if (mask & XPG_NORM_CODESET)
 143     free ((void *) normalized_codeset);
 144
 145   if (locale_file->decided == 0)
 146     _nl_load_locale (locale_file, category);
 147
 148   if (locale_file->data == NULL)
 149     {
 150       int cnt;
 151       for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
 152         {
 153           if (locale_file->successor[cnt]->decided == 0)
 154             _nl_load_locale (locale_file->successor[cnt], category);
 155           if (locale_file->successor[cnt]->data != NULL)
 156             break;
 157         }
 158       /* Move the entry we found (or NULL) to the first place of
 159          successors.  */
 160       locale_file->successor[0] = locale_file->successor[cnt];
 161       locale_file = locale_file->successor[cnt];
 162     }
 163
 164   if (locale_file == NULL)
 165     return NULL;
 166
 167   /* Determine the locale name for which loading succeeded.  This
 168      information comes from the file name.  The form is
 169      <path>/<locale>/LC_foo.  We must extract the <locale> part.  */
 170   if (((struct locale_data *) locale_file->data)->name == NULL)
 171     {
 172       char *cp, *endp;
 173
 174       endp = strrchr (locale_file->filename, '/');
 175       cp = endp - 1;
 176       while (cp[-1] != '/')
 177         --cp;
 178       ((struct locale_data *) locale_file->data)->name = __strndup (cp,
 179                                                                     endp - cp);
 180     }
 181   *name = (char *) ((struct locale_data *) locale_file->data)->name;
 182
 183   /* Increment the usage count.  */
 184   if (((struct locale_data *) locale_file->data)->usage_count
 185       < MAX_USAGE_COUNT)
 186     ++((struct locale_data *) locale_file->data)->usage_count;
 187
 188   return (struct locale_data *) locale_file->data;
 189 }
 190
 191
 192 /* Calling this function assumes the lock for handling global locale data
 193    is acquired.  */
 194 void
 195 _nl_remove_locale (int locale, struct locale_data *data)
 196 {
 197   if (--data->usage_count == 0)
 198     {
 199       /* First search the entry in the list of loaded files.  */
 200       struct loaded_l10nfile *ptr = locale_file_list[locale];
 201
 202       /* Search for the entry.  It must be in the list.  Otherwise it
 203          is a bug and we crash badly.  */
 204       while ((struct locale_data *) ptr->data != data)
 205         ptr = ptr->next;
 206
 207       /* Mark the data as not available anymore.  So when the data has
 208          to be used again it is reloaded.  */
 209       ptr->decided = 0;
 210       ptr->data = NULL;
 211
 212       /* Free the name.  */
 213       free ((char *) data->name);
 214
 215 #ifdef _POSIX_MAPPED_FILES
 216       /* Really delete the data.  First delete the real data.  */
 217       if (data->mmaped)
 218         {
 219           /* Try to unmap the area.  If this fails we mark the area as
 220              permanent.  */
 221           if (__munmap ((caddr_t) data->filedata, data->filesize) != 0)
 222             {
 223               data->usage_count = UNDELETABLE;
 224               return;
 225             }
 226         }
 227       else
 228 #endif  /* _POSIX_MAPPED_FILES */
 229         /* The memory was malloced.  */
 230         free ((void *) data->filedata);
 231
 232       /* Now free the structure itself.  */
 233       free (data);
 234     }
 235 }
 236
 237 static void __attribute__ ((unused))
 238 free_mem (void)
 239 {
 240   int category;
 241
 242   for (category = 0; category < __LC_LAST; ++category)
 243     if (category != LC_ALL)
 244       {
 245         struct loaded_l10nfile *runp = locale_file_list[category];
 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);