1 /* Handle aliases for locale names.
2    Copyright (C) 1995-1999, 2000-2001, 2003 Free Software Foundation, Inc.
3 
4    This program is free software; you can redistribute it and/or modify it
5    under the terms of the GNU Library General Public License as published
6    by the Free Software Foundation; either version 2, or (at your option)
7    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 GNU
12    Library General Public License for more details.
13 
14    You should have received a copy of the GNU Library General Public
15    License along with this program; if not, write to the Free Software
16    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
17    USA.  */
18 
19 /* Tell glibc's <string.h> to provide a prototype for mempcpy().
20    This must come before <config.h> because <config.h> may include
21    <features.h>, and once <features.h> has been included, it's too late.  */
22 #ifndef _GNU_SOURCE
23 # define _GNU_SOURCE    1
24 #endif
25 
26 #ifdef HAVE_CONFIG_H
27 # include <config.h>
28 #endif
29 
30 #include <ctype.h>
31 #include <stdio.h>
32 #if defined _LIBC || defined HAVE___FSETLOCKING
33 # include <stdio_ext.h>
34 #endif
35 #include <sys/types.h>
36 
37 #ifdef __GNUC__
38 # undef alloca
39 # define alloca __builtin_alloca
40 # define HAVE_ALLOCA 1
41 #else
42 # ifdef _MSC_VER
43 #  include <malloc.h>
44 #  define alloca _alloca
45 # else
46 #  if defined HAVE_ALLOCA_H || defined _LIBC
47 #   include <alloca.h>
48 #  else
49 #   ifdef _AIX
50  #pragma alloca
51 #   else
52 #    ifndef alloca
53 char *alloca ();
54 #    endif
55 #   endif
56 #  endif
57 # endif
58 #endif
59 
60 #include <stdlib.h>
61 #include <string.h>
62 
63 #include "gettextP.h"
64 
65 #if ENABLE_RELOCATABLE
66 # include "relocatable.h"
67 #else
68 # define relocate(pathname) (pathname)
69 #endif
70 
71 /* @@ end of prolog @@ */
72 
73 #ifdef _LIBC
74 /* Rename the non ANSI C functions.  This is required by the standard
75    because some ANSI C functions will require linking with this object
76    file and the name space must not be polluted.  */
77 # define strcasecmp __strcasecmp
78 
79 # ifndef mempcpy
80 #  define mempcpy __mempcpy
81 # endif
82 # define HAVE_MEMPCPY	1
83 # define HAVE___FSETLOCKING	1
84 
85 /* We need locking here since we can be called from different places.  */
86 # include <bits/libc-lock.h>
87 
88 __libc_lock_define_initialized (static, lock);
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 || 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 || HAVE_DECL_FEOF_UNLOCKED
118 # undef feof
119 # define feof(s) feof_unlocked (s)
120 #endif
121 
122 
123 struct alias_map
124 {
125   const char *alias;
126   const char *value;
127 };
128 
129 
130 #ifndef _LIBC
131 # define libc_freeres_ptr(decl) decl
132 #endif
133 
134 libc_freeres_ptr (static char *string_space);
135 static size_t string_space_act;
136 static size_t string_space_max;
137 libc_freeres_ptr (static struct alias_map *map);
138 static size_t nmap;
139 static size_t maxmap;
140 
141 
142 /* Prototypes for local functions.  */
143 static size_t read_alias_file (const char *fname, int fname_len)
144      internal_function;
145 static int extend_alias_table (void);
146 static int alias_compare (const struct alias_map *map1,
147 			  const struct alias_map *map2);
148 
149 
150 const char *
_nl_expand_alias(const char * name)151 _nl_expand_alias (const char *name)
152 {
153   static const char *locale_alias_path;
154   struct alias_map *retval;
155   const char *result = NULL;
156   size_t added;
157 
158 #ifdef _LIBC
159   __libc_lock_lock (lock);
160 #endif
161 
162   if (locale_alias_path == NULL)
163     locale_alias_path = LOCALE_ALIAS_PATH;
164 
165   do
166     {
167       struct alias_map item;
168 
169       item.alias = name;
170 
171       if (nmap > 0)
172 	retval = (struct alias_map *) bsearch (&item, map, nmap,
173 					       sizeof (struct alias_map),
174 					       (int (*) (const void *,
175 							 const void *)
176 						) alias_compare);
177       else
178 	retval = NULL;
179 
180       /* We really found an alias.  Return the value.  */
181       if (retval != NULL)
182 	{
183 	  result = retval->value;
184 	  break;
185 	}
186 
187       /* Perhaps we can find another alias file.  */
188       added = 0;
189       while (added == 0 && locale_alias_path[0] != '\0')
190 	{
191 	  const char *start;
192 
193 	  while (locale_alias_path[0] == PATH_SEPARATOR)
194 	    ++locale_alias_path;
195 	  start = locale_alias_path;
196 
197 	  while (locale_alias_path[0] != '\0'
198 		 && locale_alias_path[0] != PATH_SEPARATOR)
199 	    ++locale_alias_path;
200 
201 	  if (start < locale_alias_path)
202 	    added = read_alias_file (start, locale_alias_path - start);
203 	}
204     }
205   while (added != 0);
206 
207 #ifdef _LIBC
208   __libc_lock_unlock (lock);
209 #endif
210 
211   return result;
212 }
213 
214 
215 static size_t
216 internal_function
read_alias_file(const char * fname,int fname_len)217 read_alias_file (const char *fname, int fname_len)
218 {
219   FILE *fp;
220   char *full_fname;
221   size_t added;
222   static const char aliasfile[] = "/locale.alias";
223 
224   full_fname = (char *) alloca (fname_len + sizeof aliasfile);
225 #ifdef HAVE_MEMPCPY
226   mempcpy (mempcpy (full_fname, fname, fname_len),
227 	   aliasfile, sizeof aliasfile);
228 #else
229   memcpy (full_fname, fname, fname_len);
230   memcpy (&full_fname[fname_len], aliasfile, sizeof aliasfile);
231 #endif
232 
233   fp = fopen (relocate (full_fname), "r");
234   freea (full_fname);
235   if (fp == NULL)
236     return 0;
237 
238 #ifdef HAVE___FSETLOCKING
239   /* No threads present.  */
240   __fsetlocking (fp, FSETLOCKING_BYCALLER);
241 #endif
242 
243   added = 0;
244   while (!FEOF (fp))
245     {
246       /* It is a reasonable approach to use a fix buffer here because
247 	 a) we are only interested in the first two fields
248 	 b) these fields must be usable as file names and so must not
249 	    be that long
250 	 We avoid a multi-kilobyte buffer here since this would use up
251 	 stack space which we might not have if the program ran out of
252 	 memory.  */
253       char buf[400];
254       char *alias;
255       char *value;
256       char *cp;
257 
258       if (FGETS (buf, sizeof buf, fp) == NULL)
259 	/* EOF reached.  */
260 	break;
261 
262       cp = buf;
263       /* Ignore leading white space.  */
264       while (isspace ((unsigned char) cp[0]))
265 	++cp;
266 
267       /* A leading '#' signals a comment line.  */
268       if (cp[0] != '\0' && cp[0] != '#')
269 	{
270 	  alias = cp++;
271 	  while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
272 	    ++cp;
273 	  /* Terminate alias name.  */
274 	  if (cp[0] != '\0')
275 	    *cp++ = '\0';
276 
277 	  /* Now look for the beginning of the value.  */
278 	  while (isspace ((unsigned char) cp[0]))
279 	    ++cp;
280 
281 	  if (cp[0] != '\0')
282 	    {
283 	      size_t alias_len;
284 	      size_t value_len;
285 
286 	      value = cp++;
287 	      while (cp[0] != '\0' && !isspace ((unsigned char) cp[0]))
288 		++cp;
289 	      /* Terminate value.  */
290 	      if (cp[0] == '\n')
291 		{
292 		  /* This has to be done to make the following test
293 		     for the end of line possible.  We are looking for
294 		     the terminating '\n' which do not overwrite here.  */
295 		  *cp++ = '\0';
296 		  *cp = '\n';
297 		}
298 	      else if (cp[0] != '\0')
299 		*cp++ = '\0';
300 
301 	      if (nmap >= maxmap)
302 		if (__builtin_expect (extend_alias_table (), 0))
303 		  return added;
304 
305 	      alias_len = strlen (alias) + 1;
306 	      value_len = strlen (value) + 1;
307 
308 	      if (string_space_act + alias_len + value_len > string_space_max)
309 		{
310 		  /* Increase size of memory pool.  */
311 		  size_t new_size = (string_space_max
312 				     + (alias_len + value_len > 1024
313 					? alias_len + value_len : 1024));
314 		  char *new_pool = (char *) realloc (string_space, new_size);
315 		  if (new_pool == NULL)
316 		    return added;
317 
318 		  if (__builtin_expect (string_space != new_pool, 0))
319 		    {
320 		      size_t i;
321 
322 		      for (i = 0; i < nmap; i++)
323 			{
324 			  map[i].alias += new_pool - string_space;
325 			  map[i].value += new_pool - string_space;
326 			}
327 		    }
328 
329 		  string_space = new_pool;
330 		  string_space_max = new_size;
331 		}
332 
333 	      map[nmap].alias = memcpy (&string_space[string_space_act],
334 					alias, alias_len);
335 	      string_space_act += alias_len;
336 
337 	      map[nmap].value = memcpy (&string_space[string_space_act],
338 					value, value_len);
339 	      string_space_act += value_len;
340 
341 	      ++nmap;
342 	      ++added;
343 	    }
344 	}
345 
346       /* Possibly not the whole line fits into the buffer.  Ignore
347 	 the rest of the line.  */
348       while (strchr (buf, '\n') == NULL)
349 	if (FGETS (buf, sizeof buf, fp) == NULL)
350 	  /* Make sure the inner loop will be left.  The outer loop
351 	     will exit at the `feof' test.  */
352 	  break;
353     }
354 
355   /* Should we test for ferror()?  I think we have to silently ignore
356      errors.  --drepper  */
357   fclose (fp);
358 
359   if (added > 0)
360     qsort (map, nmap, sizeof (struct alias_map),
361 	   (int (*) (const void *, const void *)) alias_compare);
362 
363   return added;
364 }
365 
366 
367 static int
extend_alias_table()368 extend_alias_table ()
369 {
370   size_t new_size;
371   struct alias_map *new_map;
372 
373   new_size = maxmap == 0 ? 100 : 2 * maxmap;
374   new_map = (struct alias_map *) realloc (map, (new_size
375 						* sizeof (struct alias_map)));
376   if (new_map == NULL)
377     /* Simply don't extend: we don't have any more core.  */
378     return -1;
379 
380   map = new_map;
381   maxmap = new_size;
382   return 0;
383 }
384 
385 
386 static int
alias_compare(const struct alias_map * map1,const struct alias_map * map2)387 alias_compare (const struct alias_map *map1, const struct alias_map *map2)
388 {
389 #if defined _LIBC || defined HAVE_STRCASECMP
390   return strcasecmp (map1->alias, map2->alias);
391 #else
392   const unsigned char *p1 = (const unsigned char *) map1->alias;
393   const unsigned char *p2 = (const unsigned char *) map2->alias;
394   unsigned char c1, c2;
395 
396   if (p1 == p2)
397     return 0;
398 
399   do
400     {
401       /* I know this seems to be odd but the tolower() function in
402 	 some systems libc cannot handle nonalpha characters.  */
403       c1 = isupper (*p1) ? tolower (*p1) : *p1;
404       c2 = isupper (*p2) ? tolower (*p2) : *p2;
405       if (c1 == '\0')
406 	break;
407       ++p1;
408       ++p2;
409     }
410   while (c1 == c2);
411 
412   return c1 - c2;
413 #endif
414 }
415