1/* Copyright (C) 1996-2023 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 <assert.h>
19#include <errno.h>
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#include "../iconv/gconv_charset.h"
30#include "../iconv/gconv_int.h"
31
32
33#ifdef NL_CURRENT_INDIRECT
34# define DEFINE_CATEGORY(category, category_name, items, a) \
35extern struct __locale_data _nl_C_##category; \
36weak_extern (_nl_C_##category)
37# include "categories.def"
38# undef DEFINE_CATEGORY
39
40/* Array indexed by category of pointers to _nl_C_CATEGORY slots.
41 Elements are zero for categories whose data is never used. */
42struct __locale_data *const _nl_C[] attribute_hidden =
43 {
44# define DEFINE_CATEGORY(category, category_name, items, a) \
45 [category] = &_nl_C_##category,
46# include "categories.def"
47# undef DEFINE_CATEGORY
48 };
49#else
50# define _nl_C (_nl_C_locobj.__locales)
51#endif
52
53
54/* For each category we keep a list of records for the locale files
55 which are somehow addressed. */
56struct loaded_l10nfile *_nl_locale_file_list[__LC_LAST];
57
58const char _nl_default_locale_path[] attribute_hidden = COMPLOCALEDIR;
59
60/* Checks if the name is actually present, that is, not NULL and not
61 empty. */
62static inline int
63name_present (const char *name)
64{
65 return name != NULL && name[0] != '\0';
66}
67
68/* Checks that the locale name neither extremely long, nor contains a
69 ".." path component (to prevent directory traversal). */
70static inline int
71valid_locale_name (const char *name)
72{
73 /* Not set. */
74 size_t namelen = strlen (name);
75 /* Name too long. The limit is arbitrary and prevents stack overflow
76 issues later. */
77 if (__glibc_unlikely (namelen > 255))
78 return 0;
79 /* Directory traversal attempt. */
80 static const char slashdot[4] = {'/', '.', '.', '/'};
81 if (__glibc_unlikely (__memmem (name, namelen,
82 slashdot, sizeof (slashdot)) != NULL))
83 return 0;
84 if (namelen == 2 && __glibc_unlikely (name[0] == '.' && name [1] == '.'))
85 return 0;
86 if (namelen >= 3
87 && __glibc_unlikely (((name[0] == '.'
88 && name[1] == '.'
89 && name[2] == '/')
90 || (name[namelen - 3] == '/'
91 && name[namelen - 2] == '.'
92 && name[namelen - 1] == '.'))))
93 return 0;
94 /* If there is a slash in the name, it must start with one. */
95 if (__glibc_unlikely (memchr (name, '/', namelen) != NULL) && name[0] != '/')
96 return 0;
97 return 1;
98}
99
100struct __locale_data *
101_nl_find_locale (const char *locale_path, size_t locale_path_len,
102 int category, const char **name)
103{
104 int mask;
105 /* Name of the locale for this category. */
106 const char *cloc_name = *name;
107 const char *language;
108 const char *modifier;
109 const char *territory;
110 const char *codeset;
111 const char *normalized_codeset;
112 struct loaded_l10nfile *locale_file;
113
114 if (cloc_name[0] == '\0')
115 {
116 /* The user decides which locale to use by setting environment
117 variables. */
118 cloc_name = getenv ("LC_ALL");
119 if (!name_present (cloc_name))
120 cloc_name = getenv (_nl_category_names_get (category));
121 if (!name_present (cloc_name))
122 cloc_name = getenv ("LANG");
123 if (!name_present (cloc_name))
124 cloc_name = _nl_C_name;
125 }
126
127 /* We used to fall back to the C locale if the name contains a slash
128 character '/', but we now check for directory traversal in
129 valid_locale_name, so this is no longer necessary. */
130
131 if (__builtin_expect (strcmp (cloc_name, _nl_C_name), 1) == 0
132 || __builtin_expect (strcmp (cloc_name, _nl_POSIX_name), 1) == 0)
133 {
134 /* We need not load anything. The needed data is contained in
135 the library itself. */
136 *name = _nl_C_name;
137 return _nl_C[category];
138 }
139 else if (!valid_locale_name (cloc_name))
140 {
141 __set_errno (EINVAL);
142 return NULL;
143 }
144
145 *name = cloc_name;
146
147 /* We really have to load some data. First we try the archive,
148 but only if there was no LOCPATH environment variable specified. */
149 if (__glibc_likely (locale_path == NULL))
150 {
151 struct __locale_data *data
152 = _nl_load_locale_from_archive (category, name);
153 if (__glibc_likely (data != NULL))
154 return data;
155
156 /* Nothing in the archive with the given name. Expanding it as
157 an alias and retry. */
158 cloc_name = _nl_expand_alias (*name);
159 if (cloc_name != NULL)
160 {
161 data = _nl_load_locale_from_archive (category, &cloc_name);
162 if (__builtin_expect (data != NULL, 1))
163 return data;
164 }
165
166 /* Nothing in the archive. Set the default path to search below. */
167 locale_path = _nl_default_locale_path;
168 locale_path_len = sizeof _nl_default_locale_path;
169 }
170 else
171 /* We really have to load some data. First see whether the name is
172 an alias. Please note that this makes it impossible to have "C"
173 or "POSIX" as aliases. */
174 cloc_name = _nl_expand_alias (*name);
175
176 if (cloc_name == NULL)
177 /* It is no alias. */
178 cloc_name = *name;
179
180 /* Make a writable copy of the locale name. */
181 char *loc_name = strdupa (cloc_name);
182
183 /* LOCALE can consist of up to four recognized parts for the XPG syntax:
184
185 language[_territory[.codeset]][@modifier]
186
187 Beside the first all of them are allowed to be missing. If the
188 full specified locale is not found, the less specific one are
189 looked for. The various part will be stripped off according to
190 the following order:
191 (1) codeset
192 (2) normalized codeset
193 (3) territory
194 (4) modifier
195 */
196 mask = _nl_explode_name (loc_name, &language, &modifier, &territory,
197 &codeset, &normalized_codeset);
198 if (mask == -1)
199 /* Memory allocate problem. */
200 return NULL;
201
202 /* If exactly this locale was already asked for we have an entry with
203 the complete name. */
204 locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
205 locale_path, locale_path_len, mask,
206 language, territory, codeset,
207 normalized_codeset, modifier,
208 _nl_category_names_get (category), 0);
209
210 if (locale_file == NULL)
211 {
212 /* Find status record for addressed locale file. We have to search
213 through all directories in the locale path. */
214 locale_file = _nl_make_l10nflist (&_nl_locale_file_list[category],
215 locale_path, locale_path_len, mask,
216 language, territory, codeset,
217 normalized_codeset, modifier,
218 _nl_category_names_get (category), 1);
219 if (locale_file == NULL)
220 /* This means we are out of core. */
221 return NULL;
222 }
223
224 /* The space for normalized_codeset is dynamically allocated. Free it. */
225 if (mask & XPG_NORM_CODESET)
226 free ((void *) normalized_codeset);
227
228 if (locale_file->decided == 0)
229 _nl_load_locale (locale_file, category);
230
231 if (locale_file->data == NULL)
232 {
233 int cnt;
234 for (cnt = 0; locale_file->successor[cnt] != NULL; ++cnt)
235 {
236 if (locale_file->successor[cnt]->decided == 0)
237 _nl_load_locale (locale_file->successor[cnt], category);
238 if (locale_file->successor[cnt]->data != NULL)
239 break;
240 }
241 /* Move the entry we found (or NULL) to the first place of
242 successors. */
243 locale_file->successor[0] = locale_file->successor[cnt];
244 locale_file = locale_file->successor[cnt];
245
246 if (locale_file == NULL)
247 return NULL;
248 }
249
250 /* The LC_CTYPE category allows to check whether a locale is really
251 usable. If the locale name contains a charset name and the
252 charset name used in the locale (present in the LC_CTYPE data) is
253 not the same (after resolving aliases etc) we reject the locale
254 since using it would irritate users expecting the charset named
255 in the locale name. */
256 if (codeset != NULL)
257 {
258 /* Get the codeset information from the locale file. */
259 static const int codeset_idx[] =
260 {
261 [__LC_CTYPE] = _NL_ITEM_INDEX (CODESET),
262 [__LC_NUMERIC] = _NL_ITEM_INDEX (_NL_NUMERIC_CODESET),
263 [__LC_TIME] = _NL_ITEM_INDEX (_NL_TIME_CODESET),
264 [__LC_COLLATE] = _NL_ITEM_INDEX (_NL_COLLATE_CODESET),
265 [__LC_MONETARY] = _NL_ITEM_INDEX (_NL_MONETARY_CODESET),
266 [__LC_MESSAGES] = _NL_ITEM_INDEX (_NL_MESSAGES_CODESET),
267 [__LC_PAPER] = _NL_ITEM_INDEX (_NL_PAPER_CODESET),
268 [__LC_NAME] = _NL_ITEM_INDEX (_NL_NAME_CODESET),
269 [__LC_ADDRESS] = _NL_ITEM_INDEX (_NL_ADDRESS_CODESET),
270 [__LC_TELEPHONE] = _NL_ITEM_INDEX (_NL_TELEPHONE_CODESET),
271 [__LC_MEASUREMENT] = _NL_ITEM_INDEX (_NL_MEASUREMENT_CODESET),
272 [__LC_IDENTIFICATION] = _NL_ITEM_INDEX (_NL_IDENTIFICATION_CODESET)
273 };
274 const struct __locale_data *data;
275 const char *locale_codeset;
276 char *clocale_codeset;
277 char *ccodeset;
278
279 data = (const struct __locale_data *) locale_file->data;
280 locale_codeset =
281 (const char *) data->values[codeset_idx[category]].string;
282 assert (locale_codeset != NULL);
283 /* Note the length of the allocated memory: +3 for up to two slashes
284 and the NUL byte. */
285 clocale_codeset = (char *) alloca (strlen (locale_codeset) + 3);
286 strip (clocale_codeset, locale_codeset);
287
288 ccodeset = (char *) alloca (strlen (codeset) + 3);
289 strip (ccodeset, codeset);
290
291 if (__gconv_compare_alias (upstr (ccodeset, ccodeset),
292 upstr (clocale_codeset,
293 clocale_codeset)) != 0)
294 /* The codesets are not identical, don't use the locale. */
295 return NULL;
296 }
297
298 /* Determine the locale name for which loading succeeded. This
299 information comes from the file name. The form is
300 <path>/<locale>/LC_foo. We must extract the <locale> part. */
301 if (((const struct __locale_data *) locale_file->data)->name == NULL)
302 {
303 char *cp, *endp;
304
305 endp = strrchr (locale_file->filename, '/');
306 cp = endp - 1;
307 while (cp[-1] != '/')
308 --cp;
309 ((struct __locale_data *) locale_file->data)->name
310 = __strndup (cp, endp - cp);
311 }
312
313 /* Determine whether the user wants transliteration or not. */
314 if (modifier != NULL
315 && __strcasecmp_l (modifier, "TRANSLIT", _nl_C_locobj_ptr) == 0)
316 ((struct __locale_data *) locale_file->data)->use_translit = 1;
317
318 /* Increment the usage count. */
319 if (((const struct __locale_data *) locale_file->data)->usage_count
320 < MAX_USAGE_COUNT)
321 ++((struct __locale_data *) locale_file->data)->usage_count;
322
323 return (struct __locale_data *) locale_file->data;
324}
325
326
327/* Calling this function assumes the lock for handling global locale data
328 is acquired. */
329void
330_nl_remove_locale (int locale, struct __locale_data *data)
331{
332 if (--data->usage_count == 0)
333 {
334 if (data->alloc != ld_archive)
335 {
336 /* First search the entry in the list of loaded files. */
337 struct loaded_l10nfile *ptr = _nl_locale_file_list[locale];
338
339 /* Search for the entry. It must be in the list. Otherwise it
340 is a bug and we crash badly. */
341 while ((struct __locale_data *) ptr->data != data)
342 ptr = ptr->next;
343
344 /* Mark the data as not available anymore. So when the data has
345 to be used again it is reloaded. */
346 ptr->decided = 0;
347 ptr->data = NULL;
348 }
349
350 /* This does the real work. */
351 _nl_unload_locale (locale, data);
352 }
353}
354