1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11
12 /*
13 * Copyright 2014 Garrett D'Amore <garrett@damore.org>
14 */
15
16 /*
17 * This file implements the 2008 newlocale and friends handling.
18 */
19
20 #ifndef _LCONV_C99
21 #define _LCONV_C99
22 #endif
23
24 #include "lint.h"
25 #include <atomic.h>
26 #include <locale.h>
27 #include <sys/types.h>
28 #include <sys/mman.h>
29 #include <errno.h>
30 #include <string.h>
31 #include "libc.h"
32 #include "mtlib.h"
33 #include "tsd.h"
34 #include "localeimpl.h"
35 #include "lctype.h"
36
37 /*
38 * Big Theory of Locales:
39 *
40 * (It is recommended that readers familiarize themselves with the POSIX
41 * 2008 (XPG Issue 7) specifications for locales, first.)
42 *
43 * Historically, we had a bunch of global variables that stored locale
44 * data. While this worked well, it limited applications to a single locale
45 * at a time. This doesn't work well in certain server applications.
46 *
47 * Issue 7, X/Open introduced the concept of a locale_t object, along with
48 * versions of functions that can take this object as a parameter, along
49 * with functions to clone and manipulate these locale objects. The new
50 * functions are named with a _l() suffix.
51 *
52 * Additionally uselocale() is introduced which can change the locale of
53 * of a single thread. However, setlocale() can still be used to change
54 * the global locale.
55 *
56 * In our implementation, we use libc's TSD to store the locale data that
57 * was previously global. We still have global data because some applications
58 * have had those global objects compiled into them. (Such applications will
59 * be unable to benefit from uselocale(), btw.) The legacy routines are
60 * reimplemented as wrappers that use the appropriate locale object by
61 * calling uselocale(). uselocale() when passed a NULL pointer returns the
62 * thread-specific locale object if one is present, or the global locale
63 * object otherwise. Note that once the TSD data is set, the only way
64 * to revert to the global locale is to pass the global locale LC_GLOBAL_LOCALE
65 * to uselocale().
66 *
67 * We are careful to minimize performance impact of multiple calls to
68 * uselocale() or setlocale() by using a cache of locale data whenever possible.
69 * As a consequence of this, applications that iterate over all possible
70 * locales will burn through a lot of virtual memory, but we find such
71 * applications rare. (locale -a might be an exception, but it is short lived.)
72 */
73
74 /*
75 * NB: Each of the structures listed herein should have the refcnt
76 * set to -1, to ensure that posix locale information is never ever freed,
77 * even when changing the global locale.
78 */
79
80 typedef struct locdata *(*loadfn_t)(const char *);
81
82 static const loadfn_t loaders[LC_ALL] = {
83 __lc_ctype_load,
84 __lc_numeric_load,
85 __lc_time_load,
86 __lc_collate_load,
87 __lc_monetary_load,
88 __lc_messages_load,
89 };
90
91 extern struct lc_monetary lc_monetary_posix;
92 extern struct lc_numeric lc_numeric_posix;
93 extern struct lc_messages lc_messages_posix;
94 extern struct lc_time lc_time_posix;
95 extern struct lc_ctype lc_ctype_posix;
96 extern struct lc_collate lc_collate_posix;
97
98 static struct locale posix_locale = {
99 /* locdata */
100 .locdata = {
101 &__posix_ctype_locdata,
102 &__posix_numeric_locdata,
103 &__posix_time_locdata,
104 &__posix_collate_locdata,
105 &__posix_monetary_locdata,
106 &__posix_messages_locdata,
107 },
108 .ctype = &lc_ctype_posix,
109 .numeric = &lc_numeric_posix,
110 .collate = &lc_collate_posix,
111 .monetary = &lc_monetary_posix,
112 .messages = &lc_messages_posix,
113 .time = &lc_time_posix,
114 .runelocale = &_DefaultRuneLocale,
115 };
116
117 locale_t ___global_locale = &posix_locale;
118
119 locale_t
120 __global_locale(void)
121 {
122 return (___global_locale);
123 }
124
125 /*
126 * Category names for getenv() Note that this was modified
127 * for Solaris. See <iso/locale_iso.h>.
128 */
129 #define NUM_CATS 7
130 static char *categories[7] = {
131 "LC_CTYPE",
132 "LC_NUMERIC",
133 "LC_TIME",
134 "LC_COLLATE",
135 "LC_MONETARY",
136 "LC_MESSAGES",
137 "LC_ALL",
138 };
139
140 /*
141 * Prototypes.
142 */
143 static const char *get_locale_env(int);
144 static struct locdata *locdata_get(int, const const char *);
145 static struct locdata *locdata_get_cache(int, const char *);
146 static void locdata_set_cache(int, struct locdata *);
147
148 /*
149 * Some utility routines.
150 */
151 struct locdata *
152 __locdata_hold(struct locdata *ld)
153 {
154 if (ld != NULL && ld->l_refcnt != (uint32_t)-1)
155 atomic_inc_32(&ld->l_refcnt);
156 return (ld);
157 }
158
159 void
160 __locdata_release(struct locdata *ld)
161 {
162 if (ld->l_refcnt == (uint32_t)-1)
163 return;
164
165 if (atomic_dec_32_nv(&ld->l_refcnt) == 0) {
166 for (int i = 0; i < NLOCDATA; i++)
167 free(ld->l_data[i]);
168 if (ld->l_map && ld->l_map_len) {
169 (void) munmap(ld->l_map, ld->l_map_len);
170 }
171 free(ld);
172 }
173 }
174
175 struct locdata *
176 __locdata_alloc(const char *name, size_t memsz)
177 {
178 struct locdata *ldata;
179
180 if ((ldata = calloc(1, sizeof (*ldata))) == NULL) {
181 return (NULL);
182 }
183 if ((ldata->l_data[0] = calloc(1, memsz)) == NULL) {
184 free(ldata);
185 errno = ENOMEM;
186 return (NULL);
187 }
188 (void) strlcpy(ldata->l_lname, name, sizeof (ldata->l_lname));
189 ldata->l_refcnt = 1;
190
191 return (ldata);
192 }
193
194 /*
195 * It turns out that for performance reasons we would really like to
196 * cache the most recently referenced locale data to avoid wasteful
197 * loading from files.
198 */
199
200 static struct locdata *cache_data[LC_ALL];
201 static mutex_t cache_lock = DEFAULTMUTEX;
202
203 /*
204 * Returns the cached data if the locale name is the same. If not,
205 * returns NULL (cache miss). The locdata is returned with a hold on
206 * it, taken on behalf of the caller. The caller should drop the hold
207 * when it is finished.
208 */
209 static struct locdata *
210 locdata_get_cache(int category, const char *locname)
211 {
212 struct locdata *loc;
213
214 if (category < 0 || category >= LC_ALL)
215 return (NULL);
216
217 lmutex_lock(&cache_lock);
218 if ((loc = cache_data[category]) != NULL) {
219 if (strcmp(locname, loc->l_lname) == 0) {
220 loc = __locdata_hold(loc);
221 } else {
222 loc = NULL;
223 }
224 }
225 lmutex_unlock(&cache_lock);
226 return (loc);
227 }
228
229 /*
230 * Set the cache for the category to specific content. An additional hold
231 * is taken for the data while it is in the cache, so the caller may drop
232 * its own hold once this is complete. Also, releases the hold on any
233 * previously cached data.
234 */
235 static void
236 locdata_set_cache(int category, struct locdata *loc)
237 {
238 struct locdata *old;
239
240 if (category < 0 || category >= LC_ALL)
241 return;
242
243 lmutex_lock(&cache_lock);
244 old = cache_data[category];
245 cache_data[category] = __locdata_hold(loc);
246 lmutex_unlock(&cache_lock);
247
248 /* drop our reference on the old data */
249 if (old)
250 __locdata_release(old);
251 }
252
253 /*
254 * Routine to get the locdata for a given category and locale.
255 * This includes retrieving it from cache, retrieving it from
256 * a file, etc.
257 */
258 static struct locdata *
259 locdata_get(int category, const char *locname)
260 {
261 struct locdata *ldata;
262 char scratch[ENCODING_LEN + 1];
263 char *slash;
264 int cnt;
265 int len;
266
267 if (locname == NULL || *locname == 0) {
268 locname = get_locale_env(category);
269 }
270
271 /*
272 * Extract the locale name for the category if it is a composite
273 * locale.
274 */
275 if ((slash = strchr(locname, '/')) != NULL) {
276 for (cnt = category; cnt && slash != NULL; cnt--) {
277 locname = slash + 1;
278 slash = strchr(locname, '/');
279 }
280 if (slash) {
281 len = slash - locname;
282 if (len >= sizeof (scratch)) {
283 len = sizeof (scratch);
284 }
285 } else {
286 len = sizeof (scratch);
287 }
288 (void) strlcpy(scratch, locname, len);
289 locname = scratch;
290 }
291
292 if ((strcmp(locname, "C") == 0) || (strcmp(locname, "POSIX") == 0))
293 return (__locdata_hold(posix_locale.locdata[category]));
294
295 ldata = locdata_get_cache(category, locname);
296 if (ldata != NULL)
297 return (ldata);
298
299 /* Otherwise load it */
300 ldata = (*loaders[category])(locname);
301 if (ldata != NULL) {
302 locdata_set_cache(category, ldata);
303 }
304 return (ldata);
305 }
306
307 /* tsd destructor */
308 static void
309 freelocptr(void *arg)
310 {
311 locale_t *locptr = arg;
312 if (*locptr != NULL)
313 freelocale(*locptr);
314 }
315
316 static const char *
317 get_locale_env(int category)
318 {
319 const char *env;
320
321 /* 1. check LC_ALL. */
322 env = getenv(categories[LC_ALL]);
323
324 /* 2. check LC_* */
325 if (env == NULL || *env == '\0')
326 env = getenv(categories[category]);
327
328 /* 3. check LANG */
329 if (env == NULL || *env == '\0')
330 env = getenv("LANG");
331
332 /* 4. if none is set, fall to "C" */
333 if (env == NULL || *env == '\0')
334 env = "C";
335
336 return (env);
337 }
338
339
340 /*
341 * This routine is exposed via the MB_CUR_MAX macro. Note that legacy
342 * code will continue to use _ctype[520], but we prefer this function as
343 * it is the only way to get thread-specific information.
344 */
345 unsigned char
346 __mb_cur_max_l(locale_t loc)
347 {
348 return (loc->ctype->lc_max_mblen);
349 }
350
351 unsigned char
352 __mb_cur_max(void)
353 {
354 return (__mb_cur_max_l(uselocale(NULL)));
355 }
356
357 /*
358 * Public interfaces.
359 */
360
361 locale_t
362 duplocale(locale_t src)
363 {
364 locale_t loc;
365 int i;
366
367 loc = calloc(1, sizeof (*loc));
368 if (loc == NULL) {
369 return (NULL);
370 }
371 for (i = 0; i < LC_ALL; i++) {
372 loc->locdata[i] = __locdata_hold(src->locdata[i]);
373 loc->loaded[i] = 0;
374 }
375 loc->collate = loc->locdata[LC_COLLATE]->l_data[0];
376 loc->ctype = loc->locdata[LC_CTYPE]->l_data[0];
377 loc->runelocale = loc->locdata[LC_CTYPE]->l_data[1];
378 loc->messages = loc->locdata[LC_MESSAGES]->l_data[0];
379 loc->monetary = loc->locdata[LC_MONETARY]->l_data[0];
380 loc->numeric = loc->locdata[LC_NUMERIC]->l_data[0];
381 loc->time = loc->locdata[LC_TIME]->l_data[0];
382 return (loc);
383 }
384
385 void
386 freelocale(locale_t loc)
387 {
388 int i;
389 for (i = 0; i < LC_ALL; i++)
390 __locdata_release(loc->locdata[i]);
391 if (loc != &posix_locale)
392 free(loc);
393 }
394
395 locale_t
396 newlocale(int catmask, const char *locname, locale_t base)
397 {
398 locale_t loc;
399 int i, e;
400
401 if (catmask & ~(LC_ALL_MASK)) {
402 errno = EINVAL;
403 return (NULL);
404 }
405 loc = duplocale(base != NULL ? base : ___global_locale);
406 if (loc == NULL) {
407 return (NULL);
408 }
409
410 for (i = 0; i < LC_ALL; i++) {
411 struct locdata *ldata;
412 loc->loaded[i] = 0;
413 if (((1 << i) & catmask) == 0) {
414 /* Default to base locale if not overriding */
415 continue;
416 }
417 ldata = locdata_get(i, locname);
418 if (ldata == NULL) {
419 e = errno;
420 freelocale(loc);
421 errno = e;
422 return (NULL);
423 }
424 __locdata_release(loc->locdata[i]);
425 loc->locdata[i] = ldata;
426 }
427 if (base && base != ___global_locale) {
428 freelocale(base);
429 }
430 loc->collate = loc->locdata[LC_COLLATE]->l_data[0];
431 loc->ctype = loc->locdata[LC_CTYPE]->l_data[0];
432 loc->runelocale = loc->locdata[LC_CTYPE]->l_data[1];
433 loc->messages = loc->locdata[LC_MESSAGES]->l_data[0];
434 loc->monetary = loc->locdata[LC_MONETARY]->l_data[0];
435 loc->numeric = loc->locdata[LC_NUMERIC]->l_data[0];
436 loc->time = loc->locdata[LC_TIME]->l_data[0];
437 return (loc);
438 }
439
440 locale_t
441 uselocale(locale_t loc)
442 {
443 locale_t lastloc = ___global_locale;
444 locale_t *locptr;
445
446 locptr = tsdalloc(_T_SETLOCALE, sizeof (locale_t), freelocptr);
447 /* Should never occur */
448 if (locptr == NULL) {
449 errno = EINVAL;
450 return (NULL);
451 }
452
453 if (*locptr != NULL)
454 lastloc = *locptr;
455
456 /* Argument loc is NULL if we are just querying. */
457 if (loc != NULL) {
458 /*
459 * Set it to LC_GLOBAL_LOCAL to return to using
460 * the global locale (setlocale).
461 */
462 if (loc == ___global_locale) {
463 *locptr = NULL;
464 } else {
465 /* No validation of the provided locale at present */
466 *locptr = loc;
467 }
468 }
469
470 /*
471 * The caller is responsible for freeing, of course it would be
472 * gross error to call freelocale() on a locale object that is still
473 * in use.
474 */
475 return (lastloc);
476 }