intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995-2024 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as published by
   6    the Free Software Foundation; either version 2.1 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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
  12    GNU Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Tell glibc's <string.h> to provide a prototype for mempcpy().
  18    This must come before <config.h> because <config.h> may include
  19    <features.h>, and once <features.h> has been included, it's too late.  */
  20 #ifndef _GNU_SOURCE
  21 # define _GNU_SOURCE    1
  22 #endif
  23
  24 #ifdef HAVE_CONFIG_H
  25 # include <config.h>
  26 #endif
  27
  28 #include <ctype.h>
  29 #include <stdio.h>
  30 #if defined _LIBC || defined HAVE___FSETLOCKING
  31 # include <stdio_ext.h>
  32 #endif
  33 #include <sys/types.h>
  34
  35 #ifdef __GNUC__
  36 # undef alloca
  37 # define alloca __builtin_alloca
  38 # define HAVE_ALLOCA 1
  39 #else
  40 # ifdef _MSC_VER
  41 #  include <malloc.h>
  42 #  define alloca _alloca
  43 # else
  44 #  if defined HAVE_ALLOCA_H || defined _LIBC
  45 #   include <alloca.h>
  46 #  else
  47 #   ifdef _AIX
  48  #pragma alloca
  49 #   else
  50 #    ifndef alloca
  51 char *alloca ();
  52 #    endif
  53 #   endif
  54 #  endif
  55 # endif
  56 #endif
  57
  58 #include <stdlib.h>
  59 #include <string.h>
  60
  61 #include "gettextP.h"
  62
  63 #ifdef ENABLE_RELOCATABLE
  64 # include "relocatable.h"
  65 #else
  66 # define relocate(pathname) (pathname)
  67 #endif
  68
  69 /* @@ end of prolog @@ */
  70
  71 #ifdef _LIBC
  72 /* Rename the non ANSI C functions.  This is required by the standard
  73    because some ANSI C functions will require linking with this object
  74    file and the name space must not be polluted.  */
  75 # define strcasecmp(s1, s2) __strcasecmp_l (s1, s2, _nl_C_locobj_ptr)
  76
  77 # ifndef mempcpy
  78 #  define mempcpy __mempcpy
  79 # endif
  80 # define HAVE_MEMPCPY   1
  81 # define HAVE___FSETLOCKING     1
  82 #endif
  83
  84 /* Handle multi-threaded applications.  */
  85 #ifdef _LIBC
  86 # include <libc-lock.h>
  87 #else
  88 # include "lock.h"
  89 #endif
  90
  91 /* Some optimizations for glibc.  */
  92 #ifdef _LIBC
  93 # define FEOF(fp)               __feof_unlocked (fp)
  94 # define FGETS(buf, n, fp)      __fgets_unlocked (buf, n, fp)
  95 #else
  96 # define FEOF(fp)               feof (fp)
  97 # define FGETS(buf, n, fp)      fgets (buf, n, fp)
  98 #endif
  99
 100 /* For those losing systems which don't have `alloca' we have to add
 101    some additional code emulating it.  */
 102 #ifdef HAVE_ALLOCA
 103 # define freea(p) /* nothing */
 104 #else
 105 # define alloca(n) malloc (n)
 106 # define freea(p) free (p)
 107 #endif
 108
 109 #if defined _LIBC_REENTRANT || defined HAVE_DECL_FGETS_UNLOCKED
 110 # undef fgets
 111 # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
 112 #endif
 113 #if defined _LIBC_REENTRANT || defined HAVE_DECL_FEOF_UNLOCKED
 114 # undef feof
 115 # define feof(s) feof_unlocked (s)
 116 #endif
 117
 118
 119 __libc_lock_define_initialized (static, lock)
 120
 121
 122 struct alias_map
 123 {
 124   const char *alias;
 125   const char *value;
 126 };
 127
 128
 129 static char *string_space;
 130 static size_t string_space_act;
 131 static size_t string_space_max;
 132 static struct alias_map *map;
 133 static size_t nmap;
 134 static size_t maxmap;
 135
 136
 137 /* Prototypes for local functions.  */
 138 static size_t read_alias_file (const char *fname, int fname_len);
 139 static int extend_alias_table (void);
 140 static int alias_compare (const struct alias_map *map1,
 141                           const struct alias_map *map2);
 142
 143
 144 const char *
 145 _nl_expand_alias (const char *name)
 146 {
 147   static const char *locale_alias_path;
 148   struct alias_map *retval;
 149   const char *result = NULL;
 150   size_t added;
 151
 152   __libc_lock_lock (lock);
 153
 154   if (locale_alias_path == NULL)
 155     locale_alias_path = LOCALE_ALIAS_PATH;
 156
 157   do
 158     {
 159       struct alias_map item;
 160
 161       item.alias = name;
 162
 163       if (nmap > 0)
 164         retval = (struct alias_map *) bsearch (&item, map, nmap,
 165                                                sizeof (struct alias_map),
 166                                                (int (*) (const void *,
 167                                                          const void *)
 168                                                 ) alias_compare);
 169       else
 170         retval = NULL;
 171
 172       /* We really found an alias.  Return the value.  */
 173       if (retval != NULL)
 174         {
 175           result = retval->value;
 176           break;
 177         }
 178
 179       /* Perhaps we can find another alias file.  */
 180       added = 0;
 181       while (added == 0 && locale_alias_path[0] != '\0')
 182         {
 183           const char *start;
 184
 185           while (locale_alias_path[0] == PATH_SEPARATOR)
 186             ++locale_alias_path;
 187           start = locale_alias_path;
 188
 189           while (locale_alias_path[0] != '\0'
 190                  && locale_alias_path[0] != PATH_SEPARATOR)
 191             ++locale_alias_path;
 192
 193           if (start < locale_alias_path)
 194             added = read_alias_file (start, locale_alias_path - start);
 195         }
 196     }
 197   while (added != 0);
 198
 199   __libc_lock_unlock (lock);
 200
 201   return result;
 202 }
 203
 204
 205 static size_t
 206 read_alias_file (const char *fname, int fname_len)
 207 {
 208   FILE *fp;
 209   char *full_fname;
 210   size_t added;
 211   static const char aliasfile[] = "/locale.alias";
 212
 213   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 214 #ifdef HAVE_MEMPCPY
 215   mempcpy (mempcpy (full_fname, fname, fname_len),
 216            aliasfile, sizeof aliasfile);
 217 #else
 218   memcpy (full_fname, fname, fname_len);
 219   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 220 #endif
 221
 222 #ifdef _LIBC
 223   /* Note the file is opened with cancellation in the I/O functions
 224      disabled.  */
 225   fp = fopen (relocate (full_fname), "rce");
 226 #else
 227   fp = fopen (relocate (full_fname), "r");
 228 #endif
 229   freea (full_fname);
 230   if (fp == NULL)
 231     return 0;
 232
 233 #ifdef HAVE___FSETLOCKING
 234   /* No threads present.  */
 235   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 236 #endif
 237
 238   added = 0;
 239   while (!FEOF (fp))
 240     {
 241       /* It is a reasonable approach to use a fix buffer here because
 242          a) we are only interested in the first two fields
 243          b) these fields must be usable as file names and so must not
 244             be that long
 245          We avoid a multi-kilobyte buffer here since this would use up
 246          stack space which we might not have if the program ran out of
 247          memory.  */
 248       char buf[400];
 249       char *alias;
 250       char *value;
 251       char *cp;
 252       int complete_line;
 253
 254       if (FGETS (buf, sizeof buf, fp) == NULL)
 255         /* EOF reached.  */
 256         break;
 257
 258       /* Determine whether the line is complete.  */
 259       complete_line = strchr (buf, '\n') != NULL;
 260
 261       cp = buf;
 262       /* Ignore leading white space.  */
 263       while (isspace ((unsigned char) cp[0]))
 264         ++cp;
 265
 266       /* A leading '#' signals a comment line.  */
 267       if (cp[0] != '\0' && cp[0] != '#')
 268         {
 269           alias = cp++;
 270           while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 271             ++cp;
 272           /* Terminate alias name.  */
 273           if (cp[0] != '\0')
 274             *cp++ = '\0';
 275
 276           /* Now look for the beginning of the value.  */
 277           while (isspace ((unsigned char) cp[0]))
 278             ++cp;
 279
 280           if (cp[0] != '\0')
 281             {
 282               value = cp++;
 283               while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 284                 ++cp;
 285               /* Terminate value.  */
 286               if (cp[0] == '\n')
 287                 {
 288                   /* This has to be done to make the following test
 289                      for the end of line possible.  We are looking for
 290                      the terminating '\n' which do not overwrite here.  */
 291                   *cp++ = '\0';
 292                   *cp = '\n';
 293                 }
 294               else if (cp[0] != '\0')
 295                 *cp++ = '\0';
 296
 297 #ifdef IN_LIBGLOCALE
 298               /* glibc's locale.alias contains entries for ja_JP and ko_KR
 299                  that make it impossible to use a Japanese or Korean UTF-8
 300                  locale under the name "ja_JP" or "ko_KR".  Ignore these
 301                  entries.  */
 302               if (strchr (alias, '_') == NULL)
 303 #endif
 304                 {
 305                   size_t alias_len;
 306                   size_t value_len;
 307
 308                   if (nmap >= maxmap)
 309                     if (__builtin_expect (extend_alias_table (), 0))
 310                       goto out;
 311
 312                   alias_len = strlen (alias) + 1;
 313                   value_len = strlen (value) + 1;
 314
 315                   if (string_space_act + alias_len + value_len > string_space_max)
 316                     {
 317 #pragma GCC diagnostic push
 318
 319 #if defined __GNUC__ && __GNUC__ >= 12
 320   /* Suppress the valid GCC 12 warning until the code below is changed
 321      to avoid using pointers to the reallocated block.  */
 322 #  pragma GCC diagnostic ignored "-Wuse-after-free"
 323 #endif
 324
 325                     /* Increase size of memory pool.  */
 326                       size_t new_size = (string_space_max
 327                                          + (alias_len + value_len > 1024
 328                                             ? alias_len + value_len : 1024));
 329                       char *new_pool = (char *) realloc (string_space, new_size);
 330                       if (new_pool == NULL)
 331                         goto out;
 332
 333                       if (__builtin_expect (string_space != new_pool, 0))
 334                         {
 335                           size_t i;
 336
 337                           for (i = 0; i < nmap; i++)
 338                             {
 339                               map[i].alias += new_pool - string_space;
 340                               map[i].value += new_pool - string_space;
 341                             }
 342                         }
 343
 344                       string_space = new_pool;
 345                       string_space_max = new_size;
 346                     }
 347
 348                   map[nmap].alias =
 349                     (const char *) memcpy (&string_space[string_space_act],
 350                                            alias, alias_len);
 351                   string_space_act += alias_len;
 352
 353                   map[nmap].value =
 354                     (const char *) memcpy (&string_space[string_space_act],
 355                                            value, value_len);
 356                   string_space_act += value_len;
 357
 358 #pragma GCC diagnostic pop
 359
 360                   ++nmap;
 361                   ++added;
 362                 }
 363             }
 364         }
 365
 366       /* Possibly not the whole line fits into the buffer.  Ignore
 367          the rest of the line.  */
 368       if (! complete_line)
 369         do
 370           if (FGETS (buf, sizeof buf, fp) == NULL)
 371             /* Make sure the inner loop will be left.  The outer loop
 372                will exit at the `feof' test.  */
 373             break;
 374         while (strchr (buf, '\n') == NULL);
 375     }
 376
 377  out:
 378   /* Should we test for ferror()?  I think we have to silently ignore
 379      errors.  --drepper  */
 380   fclose (fp);
 381
 382   if (added > 0)
 383     qsort (map, nmap, sizeof (struct alias_map),
 384            (int (*) (const void *, const void *)) alias_compare);
 385
 386   return added;
 387 }
 388
 389
 390 static int
 391 extend_alias_table (void)
 392 {
 393   size_t new_size;
 394   struct alias_map *new_map;
 395
 396   new_size = maxmap == 0 ? 100 : 2 * maxmap;
 397   new_map = (struct alias_map *) realloc (map, (new_size
 398                                                 * sizeof (struct alias_map)));
 399   if (new_map == NULL)
 400     /* Simply don't extend: we don't have any more core.  */
 401     return -1;
 402
 403   map = new_map;
 404   maxmap = new_size;
 405   return 0;
 406 }
 407
 408
 409 static int
 410 alias_compare (const struct alias_map *map1, const struct alias_map *map2)
 411 {
 412 #if defined _LIBC || defined HAVE_STRCASECMP
 413   return strcasecmp (map1->alias, map2->alias);
 414 #else
 415   const unsigned char *p1 = (const unsigned char *) map1->alias;
 416   const unsigned char *p2 = (const unsigned char *) map2->alias;
 417   unsigned char c1, c2;
 418
 419   if (p1 == p2)
 420     return 0;
 421
 422   do
 423     {
 424       /* I know this seems to be odd but the tolower() function in
 425          some systems libc cannot handle nonalpha characters.  */
 426       c1 = isupper (*p1) ? tolower (*p1) : *p1;
 427       c2 = isupper (*p2) ? tolower (*p2) : *p2;
 428       if (c1 == '\0')
 429         break;
 430       ++p1;
 431       ++p2;
 432     }
 433   while (c1 == c2);
 434
 435   return c1 - c2;
 436 #endif
 437 }
 438
 439 void
 440 __libc_localealias_freemem (void)
 441 {
 442   free (string_space);
 443   free (map);
 444 }