locale/setlocale.c

   1 /* Copyright (C) 1991-2022 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <alloca.h>
  19 #include <argz.h>
  20 #include <errno.h>
  21 #include <libc-lock.h>
  22 #include <locale.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <unistd.h>
  26
  27 #include "localeinfo.h"
  28
  29 #ifdef NL_CURRENT_INDIRECT
  30
  31 /* For each category declare a special external symbol
  32    _nl_current_CATEGORY_used with a weak reference.
  33    This symbol will is defined in lc-CATEGORY.c and will be linked in
  34    if anything uses _nl_current_CATEGORY (also defined in that module).
  35    Also use a weak reference for the _nl_current_CATEGORY thread variable.  */
  36
  37 # define DEFINE_CATEGORY(category, category_name, items, a) \
  38     extern char _nl_current_##category##_used; \
  39     weak_extern (_nl_current_##category##_used) \
  40     weak_extern (_nl_current_##category)
  41 # include "categories.def"
  42 # undef DEFINE_CATEGORY
  43
  44 /* Now define a table of flags based on those special weak symbols' values.
  45    _nl_current_used[CATEGORY] will be zero if _nl_current_CATEGORY is not
  46    linked in.  */
  47 static char *const _nl_current_used[] =
  48   {
  49 # define DEFINE_CATEGORY(category, category_name, items, a) \
  50     [category] = &_nl_current_##category##_used,
  51 # include "categories.def"
  52 # undef DEFINE_CATEGORY
  53   };
  54
  55 # define CATEGORY_USED(category)        (_nl_current_used[category] != 0)
  56
  57 #else
  58
  59 /* The shared library always loads all the categories,
  60    and the current global settings are kept in _nl_global_locale.  */
  61
  62 # define CATEGORY_USED(category)        (1)
  63
  64 #endif
  65
  66
  67 /* Define an array of category names (also the environment variable names).  */
  68 const struct catnamestr_t _nl_category_names attribute_hidden =
  69   {
  70 #define DEFINE_CATEGORY(category, category_name, items, a) \
  71     category_name,
  72 #include "categories.def"
  73 #undef DEFINE_CATEGORY
  74   };
  75
  76 const uint8_t _nl_category_name_idxs[__LC_LAST] attribute_hidden =
  77   {
  78 #define DEFINE_CATEGORY(category, category_name, items, a) \
  79     [category] = offsetof (struct catnamestr_t, CATNAMEMF (__LINE__)),
  80 #include "categories.def"
  81 #undef DEFINE_CATEGORY
  82   };
  83
  84 /* An array of their lengths, for convenience.  */
  85 const uint8_t _nl_category_name_sizes[] attribute_hidden =
  86   {
  87 #define DEFINE_CATEGORY(category, category_name, items, a) \
  88     [category] = sizeof (category_name) - 1,
  89 #include "categories.def"
  90 #undef  DEFINE_CATEGORY
  91     [LC_ALL] = sizeof ("LC_ALL") - 1
  92   };
  93
  94
  95 #ifdef NL_CURRENT_INDIRECT
  96 # define WEAK_POSTLOAD(postload) weak_extern (postload)
  97 #else
  98 # define WEAK_POSTLOAD(postload) /* Need strong refs in static linking.  */
  99 #endif
 100
 101 /* Declare the postload functions used below.  */
 102 #undef  NO_POSTLOAD
 103 #define NO_POSTLOAD _nl_postload_ctype /* Harmless thing known to exist.  */
 104 #define DEFINE_CATEGORY(category, category_name, items, postload) \
 105 extern void postload (void); WEAK_POSTLOAD (postload)
 106 #include "categories.def"
 107 #undef  DEFINE_CATEGORY
 108 #undef  NO_POSTLOAD
 109
 110 /* Define an array indexed by category of postload functions to call after
 111    loading and installing that category's data.  */
 112 static void (*const _nl_category_postload[]) (void) =
 113   {
 114 #define DEFINE_CATEGORY(category, category_name, items, postload) \
 115     [category] = postload,
 116 #include "categories.def"
 117 #undef  DEFINE_CATEGORY
 118   };
 119
 120
 121 /* Lock for protecting global data.  */
 122 __libc_rwlock_define_initialized (, __libc_setlocale_lock attribute_hidden)
 123
 124 /* Defined in loadmsgcat.c.  */
 125 extern int _nl_msg_cat_cntr;
 126
 127
 128 /* Use this when we come along an error.  */
 129 #define ERROR_RETURN                                                          \
 130   do {                                                                        \
 131     __set_errno (EINVAL);                                                     \
 132     return NULL;                                                              \
 133   } while (0)
 134
 135
 136 /* Construct a new composite name.  */
 137 static char *
 138 new_composite_name (int category, const char **newnames)
 139 {
 140   size_t last_len = 0;
 141   size_t cumlen = 0;
 142   int i;
 143   char *new, *p;
 144   int same = 1;
 145
 146   for (i = 0; i < __LC_LAST; ++i)
 147     if (i != LC_ALL)
 148       {
 149         const char *name = (category == LC_ALL ? newnames[i]
 150                             : category == i ? newnames[0]
 151                             : _nl_global_locale.__names[i]);
 152         last_len = strlen (name);
 153         cumlen += _nl_category_name_sizes[i] + 1 + last_len + 1;
 154         if (same && name != newnames[0] && strcmp (name, newnames[0]) != 0)
 155           same = 0;
 156       }
 157
 158   if (same)
 159     {
 160       /* All the categories use the same name.  */
 161       if (strcmp (newnames[0], _nl_C_name) == 0
 162           || strcmp (newnames[0], _nl_POSIX_name) == 0)
 163         return (char *) _nl_C_name;
 164
 165       new = malloc (last_len + 1);
 166
 167       return new == NULL ? NULL : memcpy (new, newnames[0], last_len + 1);
 168     }
 169
 170   new = malloc (cumlen);
 171   if (new == NULL)
 172     return NULL;
 173   p = new;
 174   for (i = 0; i < __LC_LAST; ++i)
 175     if (i != LC_ALL)
 176       {
 177         /* Add "CATEGORY=NAME;" to the string.  */
 178         const char *name = (category == LC_ALL ? newnames[i]
 179                             : category == i ? newnames[0]
 180                             : _nl_global_locale.__names[i]);
 181         p = __stpcpy (p, _nl_category_names_get (i));
 182         *p++ = '=';
 183         p = __stpcpy (p, name);
 184         *p++ = ';';
 185       }
 186   p[-1] = '\0';         /* Clobber the last ';'.  */
 187   return new;
 188 }
 189
 190
 191 /* Put NAME in _nl_global_locale.__names.  */
 192 static void
 193 setname (int category, const char *name)
 194 {
 195   if (_nl_global_locale.__names[category] == name)
 196     return;
 197
 198   if (_nl_global_locale.__names[category] != _nl_C_name)
 199     free ((char *) _nl_global_locale.__names[category]);
 200
 201   _nl_global_locale.__names[category] = name;
 202 }
 203
 204 /* Put DATA in *_nl_current[CATEGORY].  */
 205 static void
 206 setdata (int category, struct __locale_data *data)
 207 {
 208   if (CATEGORY_USED (category))
 209     {
 210       _nl_global_locale.__locales[category] = data;
 211       if (_nl_category_postload[category])
 212         (*_nl_category_postload[category]) ();
 213     }
 214 }
 215
 216 char *
 217 setlocale (int category, const char *locale)
 218 {
 219   char *locale_path;
 220   size_t locale_path_len;
 221   const char *locpath_var;
 222   char *composite;
 223
 224   /* Sanity check for CATEGORY argument.  */
 225   if (__builtin_expect (category, 0) < 0
 226       || __builtin_expect (category, 0) >= __LC_LAST)
 227     ERROR_RETURN;
 228
 229   /* Does user want name of current locale?  */
 230   if (locale == NULL)
 231     return (char *) _nl_global_locale.__names[category];
 232
 233   /* Protect global data.  */
 234   __libc_rwlock_wrlock (__libc_setlocale_lock);
 235
 236   if (strcmp (locale, _nl_global_locale.__names[category]) == 0)
 237     {
 238       /* Changing to the same thing.  */
 239       __libc_rwlock_unlock (__libc_setlocale_lock);
 240
 241       return (char *) _nl_global_locale.__names[category];
 242     }
 243
 244   /* We perhaps really have to load some data.  So we determine the
 245      path in which to look for the data now.  The environment variable
 246      `LOCPATH' must only be used when the binary has no SUID or SGID
 247      bit set.  If using the default path, we tell _nl_find_locale
 248      by passing null and it can check the canonical locale archive.  */
 249   locale_path = NULL;
 250   locale_path_len = 0;
 251
 252   locpath_var = getenv ("LOCPATH");
 253   if (locpath_var != NULL && locpath_var[0] != '\0')
 254     {
 255       if (__argz_create_sep (locpath_var, ':',
 256                              &locale_path, &locale_path_len) != 0
 257           || __argz_add_sep (&locale_path, &locale_path_len,
 258                              _nl_default_locale_path, ':') != 0)
 259         {
 260           __libc_rwlock_unlock (__libc_setlocale_lock);
 261           return NULL;
 262         }
 263     }
 264
 265   if (category == LC_ALL)
 266     {
 267       /* The user wants to set all categories.  The desired locales
 268          for the individual categories can be selected by using a
 269          composite locale name.  This is a semi-colon separated list
 270          of entries of the form `CATEGORY=VALUE'.  */
 271       const char *newnames[__LC_LAST];
 272       struct __locale_data *newdata[__LC_LAST];
 273       /* Copy of the locale argument, for in-place splitting.  */
 274       char *locale_copy = NULL;
 275
 276       /* Set all name pointers to the argument name.  */
 277       for (category = 0; category < __LC_LAST; ++category)
 278         if (category != LC_ALL)
 279           newnames[category] = (char *) locale;
 280
 281       if (__glibc_unlikely (strchr (locale, ';') != NULL))
 282         {
 283           /* This is a composite name.  Make a copy and split it up.  */
 284           locale_copy = __strdup (locale);
 285           if (__glibc_unlikely (locale_copy == NULL))
 286             {
 287               __libc_rwlock_unlock (__libc_setlocale_lock);
 288               return NULL;
 289             }
 290           char *np = locale_copy;
 291           char *cp;
 292           int cnt;
 293
 294           while ((cp = strchr (np, '=')) != NULL)
 295             {
 296               for (cnt = 0; cnt < __LC_LAST; ++cnt)
 297                 if (cnt != LC_ALL
 298                     && (size_t) (cp - np) == _nl_category_name_sizes[cnt]
 299                     && (memcmp (np, (_nl_category_names_get (cnt)), cp - np)
 300                         == 0))
 301                   break;
 302
 303               if (cnt == __LC_LAST)
 304                 {
 305                 error_return:
 306                   __libc_rwlock_unlock (__libc_setlocale_lock);
 307                   free (locale_copy);
 308
 309                   /* Bogus category name.  */
 310                   ERROR_RETURN;
 311                 }
 312
 313               /* Found the category this clause sets.  */
 314               newnames[cnt] = ++cp;
 315               cp = strchr (cp, ';');
 316               if (cp != NULL)
 317                 {
 318                   /* Examine the next clause.  */
 319                   *cp = '\0';
 320                   np = cp + 1;
 321                 }
 322               else
 323                 /* This was the last clause.  We are done.  */
 324                 break;
 325             }
 326
 327           for (cnt = 0; cnt < __LC_LAST; ++cnt)
 328             if (cnt != LC_ALL && newnames[cnt] == locale)
 329               /* The composite name did not specify all categories.  */
 330               goto error_return;
 331         }
 332
 333       /* Load the new data for each category.  */
 334       while (category-- > 0)
 335         if (category != LC_ALL)
 336           {
 337             newdata[category] = _nl_find_locale (locale_path, locale_path_len,
 338                                                  category,
 339                                                  &newnames[category]);
 340
 341             if (newdata[category] == NULL)
 342               {
 343 #ifdef NL_CURRENT_INDIRECT
 344                 if (newnames[category] == _nl_C_name)
 345                   /* Null because it's the weak value of _nl_C_LC_FOO.  */
 346                   continue;
 347 #endif
 348                 break;
 349               }
 350
 351             /* We must not simply free a global locale since we have
 352                no control over the usage.  So we mark it as
 353                un-deletable.  And yes, the 'if' is needed, the data
 354                might be in read-only memory.  */
 355             if (newdata[category]->usage_count != UNDELETABLE)
 356               newdata[category]->usage_count = UNDELETABLE;
 357
 358             /* Make a copy of locale name.  */
 359             if (newnames[category] != _nl_C_name)
 360               {
 361                 if (strcmp (newnames[category],
 362                             _nl_global_locale.__names[category]) == 0)
 363                   newnames[category] = _nl_global_locale.__names[category];
 364                 else
 365                   {
 366                     newnames[category] = __strdup (newnames[category]);
 367                     if (newnames[category] == NULL)
 368                       break;
 369                   }
 370               }
 371           }
 372
 373       /* Create new composite name.  */
 374       composite = (category >= 0
 375                    ? NULL : new_composite_name (LC_ALL, newnames));
 376       if (composite != NULL)
 377         {
 378           /* Now we have loaded all the new data.  Put it in place.  */
 379           for (category = 0; category < __LC_LAST; ++category)
 380             if (category != LC_ALL)
 381               {
 382                 setdata (category, newdata[category]);
 383                 setname (category, newnames[category]);
 384               }
 385           setname (LC_ALL, composite);
 386
 387           /* We successfully loaded a new locale.  Let the message catalog
 388              functions know about this.  */
 389           ++_nl_msg_cat_cntr;
 390         }
 391       else
 392         for (++category; category < __LC_LAST; ++category)
 393           if (category != LC_ALL && newnames[category] != _nl_C_name
 394               && newnames[category] != _nl_global_locale.__names[category])
 395             free ((char *) newnames[category]);
 396
 397       /* Critical section left.  */
 398       __libc_rwlock_unlock (__libc_setlocale_lock);
 399
 400       /* Free the resources.  */
 401       free (locale_path);
 402       free (locale_copy);
 403
 404       return composite;
 405     }
 406   else
 407     {
 408       struct __locale_data *newdata = NULL;
 409       const char *newname[1] = { locale };
 410
 411       if (CATEGORY_USED (category))
 412         {
 413           /* Only actually load the data if anything will use it.  */
 414           newdata = _nl_find_locale (locale_path, locale_path_len, category,
 415                                      &newname[0]);
 416           if (newdata == NULL)
 417             goto abort_single;
 418
 419           /* We must not simply free a global locale since we have no
 420              control over the usage.  So we mark it as un-deletable.
 421
 422              Note: do not remove the `if', it's necessary to cope with
 423              the builtin locale data.  */
 424           if (newdata->usage_count != UNDELETABLE)
 425             newdata->usage_count = UNDELETABLE;
 426         }
 427
 428       /* Make a copy of locale name.  */
 429       if (newname[0] != _nl_C_name)
 430         {
 431           newname[0] = __strdup (newname[0]);
 432           if (newname[0] == NULL)
 433             goto abort_single;
 434         }
 435
 436       /* Create new composite name.  */
 437       composite = new_composite_name (category, newname);
 438       if (composite == NULL)
 439         {
 440           if (newname[0] != _nl_C_name)
 441             free ((char *) newname[0]);
 442
 443           /* Say that we don't have any data loaded.  */
 444         abort_single:
 445           newname[0] = NULL;
 446         }
 447       else
 448         {
 449           if (CATEGORY_USED (category))
 450             setdata (category, newdata);
 451
 452           setname (category, newname[0]);
 453           setname (LC_ALL, composite);
 454
 455           /* We successfully loaded a new locale.  Let the message catalog
 456              functions know about this.  */
 457           ++_nl_msg_cat_cntr;
 458         }
 459
 460       /* Critical section left.  */
 461       __libc_rwlock_unlock (__libc_setlocale_lock);
 462
 463       /* Free the resources (the locale path variable.  */
 464       free (locale_path);
 465
 466       return (char *) newname[0];
 467     }
 468 }
 469 libc_hidden_def (setlocale)
 470
 471 static void __libc_freeres_fn_section
 472 free_category (int category,
 473                struct __locale_data *here, struct __locale_data *c_data)
 474 {
 475   struct loaded_l10nfile *runp = _nl_locale_file_list[category];
 476
 477   /* If this category is already "C" don't do anything.  */
 478   if (here != c_data)
 479     {
 480       /* We have to be prepared that sometime later we still
 481          might need the locale information.  */
 482       setdata (category, c_data);
 483       setname (category, _nl_C_name);
 484     }
 485
 486   while (runp != NULL)
 487     {
 488       struct loaded_l10nfile *curr = runp;
 489       struct __locale_data *data = (struct __locale_data *) runp->data;
 490
 491       if (data != NULL && data != c_data)
 492         _nl_unload_locale (category, data);
 493       runp = runp->next;
 494       free ((char *) curr->filename);
 495       free (curr);
 496     }
 497 }
 498
 499 /* This is called from iconv/gconv_db.c's free_mem, as locales must
 500    be freed before freeing gconv steps arrays.  */
 501 void __libc_freeres_fn_section
 502 _nl_locale_subfreeres (void)
 503 {
 504 #ifdef NL_CURRENT_INDIRECT
 505   /* We don't use the loop because we want to have individual weak
 506      symbol references here.  */
 507 # define DEFINE_CATEGORY(category, category_name, items, a)                   \
 508   if (CATEGORY_USED (category))                                               \
 509     {                                                                         \
 510       extern struct __locale_data _nl_C_##category;                           \
 511       weak_extern (_nl_C_##category)                                          \
 512       free_category (category, *_nl_current_##category, &_nl_C_##category);   \
 513     }
 514 # include "categories.def"
 515 # undef DEFINE_CATEGORY
 516 #else
 517   int category;
 518
 519   for (category = 0; category < __LC_LAST; ++category)
 520     if (category != LC_ALL)
 521       free_category (category, _NL_CURRENT_DATA (category),
 522                      _nl_C_locobj.__locales[category]);
 523 #endif
 524
 525   setname (LC_ALL, _nl_C_name);
 526
 527   /* This frees the data structures associated with the locale archive.
 528      The locales from the archive are not in the file list, so we have
 529      not called _nl_unload_locale on them above.  */
 530   _nl_archive_subfreeres ();
 531 }