intl/localealias.c

   1 /* Handle aliases for locale names.
   2    Copyright (C) 1995-2017 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 <http://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 #ifndef internal_function
  92 # define internal_function
  93 #endif
  94
  95 /* Some optimizations for glibc.  */
  96 #ifdef _LIBC
  97 # define FEOF(fp)               feof_unlocked (fp)
  98 # define FGETS(buf, n, fp)      __fgets_unlocked (buf, n, fp)
  99 #else
 100 # define FEOF(fp)               feof (fp)
 101 # define FGETS(buf, n, fp)      fgets (buf, n, fp)
 102 #endif
 103
 104 /* For those losing systems which don't have `alloca' we have to add
 105    some additional code emulating it.  */
 106 #ifdef HAVE_ALLOCA
 107 # define freea(p) /* nothing */
 108 #else
 109 # define alloca(n) malloc (n)
 110 # define freea(p) free (p)
 111 #endif
 112
 113 #if defined _LIBC_REENTRANT || defined HAVE_DECL_FGETS_UNLOCKED
 114 # undef fgets
 115 # define fgets(buf, len, s) fgets_unlocked (buf, len, s)
 116 #endif
 117 #if defined _LIBC_REENTRANT || defined HAVE_DECL_FEOF_UNLOCKED
 118 # undef feof
 119 # define feof(s) feof_unlocked (s)
 120 #endif
 121
 122
 123 __libc_lock_define_initialized (static, lock)
 124
 125
 126 struct alias_map
 127 {
 128   const char *alias;
 129   const char *value;
 130 };
 131
 132
 133 #ifndef _LIBC
 134 # define libc_freeres_ptr(decl) decl
 135 #endif
 136
 137 libc_freeres_ptr (static char *string_space);
 138 static size_t string_space_act;
 139 static size_t string_space_max;
 140 libc_freeres_ptr (static struct alias_map *map);
 141 static size_t nmap;
 142 static size_t maxmap;
 143
 144
 145 /* Prototypes for local functions.  */
 146 static size_t read_alias_file (const char *fname, int fname_len)
 147      internal_function;
 148 static int extend_alias_table (void);
 149 static int alias_compare (const struct alias_map *map1,
 150                           const struct alias_map *map2);
 151
 152
 153 const char *
 154 _nl_expand_alias (const char *name)
 155 {
 156   static const char *locale_alias_path;
 157   struct alias_map *retval;
 158   const char *result = NULL;
 159   size_t added;
 160
 161   __libc_lock_lock (lock);
 162
 163   if (locale_alias_path == NULL)
 164     locale_alias_path = LOCALE_ALIAS_PATH;
 165
 166   do
 167     {
 168       struct alias_map item;
 169
 170       item.alias = name;
 171
 172       if (nmap > 0)
 173         retval = (struct alias_map *) bsearch (&item, map, nmap,
 174                                                sizeof (struct alias_map),
 175                                                (int (*) (const void *,
 176                                                          const void *)
 177                                                 ) alias_compare);
 178       else
 179         retval = NULL;
 180
 181       /* We really found an alias.  Return the value.  */
 182       if (retval != NULL)
 183         {
 184           result = retval->value;
 185           break;
 186         }
 187
 188       /* Perhaps we can find another alias file.  */
 189       added = 0;
 190       while (added == 0 && locale_alias_path[0] != '\0')
 191         {
 192           const char *start;
 193
 194           while (locale_alias_path[0] == PATH_SEPARATOR)
 195             ++locale_alias_path;
 196           start = locale_alias_path;
 197
 198           while (locale_alias_path[0] != '\0'
 199                  && locale_alias_path[0] != PATH_SEPARATOR)
 200             ++locale_alias_path;
 201
 202           if (start < locale_alias_path)
 203             added = read_alias_file (start, locale_alias_path - start);
 204         }
 205     }
 206   while (added != 0);
 207
 208   __libc_lock_unlock (lock);
 209
 210   return result;
 211 }
 212
 213
 214 static size_t
 215 internal_function
 216 read_alias_file (const char *fname, int fname_len)
 217 {
 218   FILE *fp;
 219   char *full_fname;
 220   size_t added;
 221   static const char aliasfile[] = "/locale.alias";
 222
 223   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
 224 #ifdef HAVE_MEMPCPY
 225   mempcpy (mempcpy (full_fname, fname, fname_len),
 226            aliasfile, sizeof aliasfile);
 227 #else
 228   memcpy (full_fname, fname, fname_len);
 229   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
 230 #endif
 231
 232 #ifdef _LIBC
 233   /* Note the file is opened with cancellation in the I/O functions
 234      disabled.  */
 235   fp = fopen (relocate (full_fname), "rce");
 236 #else
 237   fp = fopen (relocate (full_fname), "r");
 238 #endif
 239   freea (full_fname);
 240   if (fp == NULL)
 241     return 0;
 242
 243 #ifdef HAVE___FSETLOCKING
 244   /* No threads present.  */
 245   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 246 #endif
 247
 248   added = 0;
 249   while (!FEOF (fp))
 250     {
 251       /* It is a reasonable approach to use a fix buffer here because
 252          a) we are only interested in the first two fields
 253          b) these fields must be usable as file names and so must not
 254             be that long
 255          We avoid a multi-kilobyte buffer here since this would use up
 256          stack space which we might not have if the program ran out of
 257          memory.  */
 258       char buf[400];
 259       char *alias;
 260       char *value;
 261       char *cp;
 262       int complete_line;
 263
 264       if (FGETS (buf, sizeof buf, fp) == NULL)
 265         /* EOF reached.  */
 266         break;
 267
 268       /* Determine whether the line is complete.  */
 269       complete_line = strchr (buf, '\n') != NULL;
 270
 271       cp = buf;
 272       /* Ignore leading white space.  */
 273       while (isspace ((unsigned char) cp[0]))
 274         ++cp;
 275
 276       /* A leading '#' signals a comment line.  */
 277       if (cp[0] != '\0' && cp[0] != '#')
 278         {
 279           alias = cp++;
 280           while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 281             ++cp;
 282           /* Terminate alias name.  */
 283           if (cp[0] != '\0')
 284             *cp++ = '\0';
 285
 286           /* Now look for the beginning of the value.  */
 287           while (isspace ((unsigned char) cp[0]))
 288             ++cp;
 289
 290           if (cp[0] != '\0')
 291             {
 292               value = cp++;
 293               while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
 294                 ++cp;
 295               /* Terminate value.  */
 296               if (cp[0] == '\n')
 297                 {
 298                   /* This has to be done to make the following test
 299                      for the end of line possible.  We are looking for
 300                      the terminating '\n' which do not overwrite here.  */
 301                   *cp++ = '\0';
 302                   *cp = '\n';
 303                 }
 304               else if (cp[0] != '\0')
 305                 *cp++ = '\0';
 306
 307 #ifdef IN_LIBGLOCALE
 308               /* glibc's locale.alias contains entries for ja_JP and ko_KR
 309                  that make it impossible to use a Japanese or Korean UTF-8
 310                  locale under the name "ja_JP" or "ko_KR".  Ignore these
 311                  entries.  */
 312               if (strchr (alias, '_') == NULL)
 313 #endif
 314                 {
 315                   size_t alias_len;
 316                   size_t value_len;
 317
 318                   if (nmap >= maxmap)
 319                     if (__builtin_expect (extend_alias_table (), 0))
 320                       goto out;
 321
 322                   alias_len = strlen (alias) + 1;
 323                   value_len = strlen (value) + 1;
 324
 325                   if (string_space_act + alias_len + value_len > string_space_max)
 326                     {
 327                       /* Increase size of memory pool.  */
 328                       size_t new_size = (string_space_max
 329                                          + (alias_len + value_len > 1024
 330                                             ? alias_len + value_len : 1024));
 331                       char *new_pool = (char *) realloc (string_space, new_size);
 332                       if (new_pool == NULL)
 333                         goto out;
 334
 335                       if (__builtin_expect (string_space != new_pool, 0))
 336                         {
 337                           size_t i;
 338
 339                           for (i = 0; i < nmap; i++)
 340                             {
 341                               map[i].alias += new_pool - string_space;
 342                               map[i].value += new_pool - string_space;
 343                             }
 344                         }
 345
 346                       string_space = new_pool;
 347                       string_space_max = new_size;
 348                     }
 349
 350                   map[nmap].alias =
 351                     (const char *) memcpy (&string_space[string_space_act],
 352                                            alias, alias_len);
 353                   string_space_act += alias_len;
 354
 355                   map[nmap].value =
 356                     (const char *) memcpy (&string_space[string_space_act],
 357                                            value, value_len);
 358                   string_space_act += value_len;
 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 }