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 * Category data is never released (although enclosing locale objects might be),
74 * in order to guarantee thread-safety. Calling freelocale() on an object
75 * while it is in use by another thread is a programmer error (use-after-free)
76 * and we don't bother to note it further.
77 *
78 * Locale objects (global locales) established by setlocale() are also
79 * never freed (for MT safety), but we will save previous locale objects
80 * and reuse them when we can.
81 */
82
83 typedef struct locdata *(*loadfn_t)(const char *);
84
85 static const loadfn_t loaders[LC_ALL] = {
86 __lc_ctype_load,
87 __lc_numeric_load,
88 __lc_time_load,
89 __lc_collate_load,
90 __lc_monetary_load,
91 __lc_messages_load,
92 };
93
94 extern struct lc_monetary lc_monetary_posix;
95 extern struct lc_numeric lc_numeric_posix;
96 extern struct lc_messages lc_messages_posix;
97 extern struct lc_time lc_time_posix;
98 extern struct lc_ctype lc_ctype_posix;
99 extern struct lc_collate lc_collate_posix;
100 extern struct _RuneLocale _DefaultRuneLocale;
101
102 static struct _locale posix_locale = {
103 /* locdata */
104 .locdata = {
105 &__posix_ctype_locdata,
106 &__posix_numeric_locdata,
107 &__posix_time_locdata,
108 &__posix_collate_locdata,
109 &__posix_monetary_locdata,
110 &__posix_messages_locdata,
111 },
112 .locname = "C",
113 .ctype = &lc_ctype_posix,
114 .numeric = &lc_numeric_posix,
115 .collate = &lc_collate_posix,
116 .monetary = &lc_monetary_posix,
117 .messages = &lc_messages_posix,
118 .time = &lc_time_posix,
119 .runelocale = &_DefaultRuneLocale,
120 };
121
122 locale_t ___global_locale = &posix_locale;
123
124 locale_t
__global_locale(void)125 __global_locale(void)
126 {
127 return (___global_locale);
128 }
129
130 /*
131 * Locale data for hybrid C.UTF-8 locale having all the characteristics of
132 * default C/POSIX locale, except for LC_CTYPE data which is retrieved from
133 * cache/file as for other UTF-8 locales.
134 */
135 static struct locdata cutf_locdata[LC_ALL] = {
136 { "C.UTF-8", NULL }, /* unused */
137 { "C.UTF-8", &lc_numeric_posix },
138 { "C.UTF-8", &lc_time_posix },
139 { "C.UTF-8", &lc_collate_posix },
140 { "C.UTF-8", &lc_monetary_posix },
141 { "C.UTF-8", &lc_messages_posix },
142 };
143
144 /*
145 * Category names for getenv() Note that this was modified
146 * for Solaris. See <iso/locale_iso.h>.
147 */
148 #define NUM_CATS 7
149 static char *categories[7] = {
150 "LC_CTYPE",
151 "LC_NUMERIC",
152 "LC_TIME",
153 "LC_COLLATE",
154 "LC_MONETARY",
155 "LC_MESSAGES",
156 "LC_ALL",
157 };
158
159 /*
160 * Prototypes.
161 */
162 static const char *get_locale_env(int);
163 static struct locdata *locdata_get(int, const char *);
164 static struct locdata *locdata_get_cache(int, const char *);
165 static locale_t mklocname(locale_t);
166
167 /*
168 * Some utility routines.
169 */
170
171 struct locdata *
__locdata_alloc(const char * name,size_t memsz)172 __locdata_alloc(const char *name, size_t memsz)
173 {
174 struct locdata *ldata;
175
176 if ((ldata = lmalloc(sizeof (*ldata))) == NULL) {
177 return (NULL);
178 }
179 if ((ldata->l_data[0] = libc_malloc(memsz)) == NULL) {
180 lfree(ldata, sizeof (*ldata));
181 errno = ENOMEM;
182 return (NULL);
183 }
184 (void) strlcpy(ldata->l_lname, name, sizeof (ldata->l_lname));
185
186 return (ldata);
187 }
188
189 /*
190 * Normally we never free locale data truly, but if we failed to load it
191 * for some reason, this routine is used to cleanup the partial mess.
192 */
193 void
__locdata_free(struct locdata * ldata)194 __locdata_free(struct locdata *ldata)
195 {
196 for (int i = 0; i < NLOCDATA; i++)
197 libc_free(ldata->l_data[i]);
198 if (ldata->l_map != NULL && ldata->l_map_len)
199 (void) munmap(ldata->l_map, ldata->l_map_len);
200 lfree(ldata, sizeof (*ldata));
201 }
202
203 /*
204 * It turns out that for performance reasons we would really like to
205 * cache the most recently referenced locale data to avoid wasteful
206 * loading from files.
207 */
208
209 static struct locdata *cache_data[LC_ALL];
210 static struct locdata *cat_data[LC_ALL];
211 static mutex_t cache_lock = DEFAULTMUTEX;
212
213 /*
214 * Returns the cached data if the locale name is the same. If not,
215 * returns NULL (cache miss). The locdata is returned with a hold on
216 * it, taken on behalf of the caller. The caller should drop the hold
217 * when it is finished.
218 */
219 static struct locdata *
locdata_get_cache(int category,const char * locname)220 locdata_get_cache(int category, const char *locname)
221 {
222 struct locdata *loc;
223
224 if (category < 0 || category >= LC_ALL)
225 return (NULL);
226
227 /* Try cache first. */
228 lmutex_lock(&cache_lock);
229 loc = cache_data[category];
230
231 if ((loc != NULL) && (strcmp(loc->l_lname, locname) == 0)) {
232 lmutex_unlock(&cache_lock);
233 return (loc);
234 }
235
236 /*
237 * Failing that try previously loaded locales (linear search) --
238 * this could be optimized to a hash, but its unlikely that a single
239 * application will ever need to work with more than a few locales.
240 */
241 for (loc = cat_data[category]; loc != NULL; loc = loc->l_next) {
242 if (strcmp(locname, loc->l_lname) == 0) {
243 break;
244 }
245 }
246
247 /*
248 * Finally, if we still don't have one, try loading the locale
249 * data from the actual on-disk data.
250 *
251 * We drop the lock (libc wants to ensure no internal locks
252 * are held when we call other routines required to read from
253 * files, allocate memory, etc.) There is a small race here,
254 * but the consequences of the race are benign -- if multiple
255 * threads hit this at precisely the same point, we could
256 * wind up with duplicates of the locale data in the cache.
257 *
258 * This wastes the memory for an extra copy of the locale
259 * data, but there is no further harm beyond that. Its not
260 * worth the effort to recode this to something "safe"
261 * (which would require rescanning the list, etc.), given
262 * that this race will probably never actually occur.
263 */
264 if (loc == NULL) {
265 lmutex_unlock(&cache_lock);
266 loc = (*loaders[category])(locname);
267 lmutex_lock(&cache_lock);
268 if (loc != NULL)
269 (void) strlcpy(loc->l_lname, locname,
270 sizeof (loc->l_lname));
271 }
272
273 /*
274 * Assuming we got one, update the cache, and stick us on the list
275 * of loaded locale data. We insert into the head (more recent
276 * use is likely to win.)
277 */
278 if (loc != NULL) {
279 cache_data[category] = loc;
280 if (!loc->l_cached) {
281 loc->l_cached = 1;
282 loc->l_next = cat_data[category];
283 cat_data[category] = loc;
284 }
285 }
286
287 lmutex_unlock(&cache_lock);
288 return (loc);
289 }
290
291 /* Charmap aliases, mostly found in Linux */
292 static const struct {
293 const char *alias;
294 const char *name;
295 } cmalias[] = {
296 { "utf8", "UTF-8" },
297 { "iso88591", "ISO8859-1" },
298 { "iso885915", "ISO8859-15" },
299 { "gb18030", "GB18030" },
300 { "koi8r", "KOI8-R" },
301 { NULL, NULL }
302 };
303
304 /*
305 * Routine to get the locdata for a given category and locale.
306 * This includes retrieving it from cache, retrieving it from
307 * a file, etc.
308 */
309 static struct locdata *
locdata_get(int category,const char * locname)310 locdata_get(int category, const char *locname)
311 {
312 char scratch[ENCODING_LEN + 1];
313 char scratch2[ENCODING_LEN + 1];
314 char *slash, *cm;
315 int cnt;
316 int len;
317 int i;
318
319 if (locname == NULL || *locname == 0) {
320 locname = get_locale_env(category);
321 }
322
323 /*
324 * Extract the locale name for the category if it is a composite
325 * locale.
326 */
327 if ((slash = strchr(locname, '/')) != NULL) {
328 for (cnt = category; cnt && slash != NULL; cnt--) {
329 locname = slash + 1;
330 slash = strchr(locname, '/');
331 }
332 if (slash) {
333 len = slash - locname + 1;
334 if (len >= sizeof (scratch)) {
335 len = sizeof (scratch);
336 }
337 } else {
338 len = sizeof (scratch);
339 }
340 (void) strlcpy(scratch, locname, len);
341 locname = scratch;
342 }
343
344 if ((strcmp(locname, "C") == 0) || (strcmp(locname, "POSIX") == 0))
345 return (posix_locale.locdata[category]);
346
347 /* Handle charmap aliases */
348 for (i = 0; cmalias[i].alias != NULL; i++) {
349 if ((cm = strstr(locname, cmalias[i].alias)) != NULL &&
350 strlen(cm) == strlen(cmalias[i].alias)) {
351 len = cm - locname + 1;
352 if (len + strlen(cmalias[i].name) >= sizeof (scratch2))
353 break;
354 (void) strlcpy(scratch2, locname, len);
355 (void) strlcat(scratch2, cmalias[i].name,
356 sizeof (scratch2));
357 locname = scratch2;
358 break;
359 }
360 }
361
362 if ((strcmp(locname, "C.UTF-8") == 0) && (category != LC_CTYPE))
363 return (&cutf_locdata[category]);
364
365 return (locdata_get_cache(category, locname));
366 }
367
368 /* tsd destructor */
369 static void
freelocptr(void * arg)370 freelocptr(void *arg)
371 {
372 locale_t *locptr = arg;
373 if (*locptr != NULL)
374 freelocale(*locptr);
375 }
376
377 static const char *
get_locale_env(int category)378 get_locale_env(int category)
379 {
380 const char *env;
381
382 /* 1. check LC_ALL. */
383 env = getenv(categories[LC_ALL]);
384
385 /* 2. check LC_* */
386 if (env == NULL || *env == '\0')
387 env = getenv(categories[category]);
388
389 /* 3. check LANG */
390 if (env == NULL || *env == '\0')
391 env = getenv("LANG");
392
393 /* 4. if none is set, fall to "C" */
394 if (env == NULL || *env == '\0')
395 env = "C";
396
397 return (env);
398 }
399
400
401 /*
402 * This routine is exposed via the MB_CUR_MAX macro. Note that legacy
403 * code will continue to use _ctype[520], but we prefer this function as
404 * it is the only way to get thread-specific information.
405 */
406 unsigned char
__mb_cur_max_l(locale_t loc)407 __mb_cur_max_l(locale_t loc)
408 {
409 return (loc->ctype->lc_max_mblen);
410 }
411
412 unsigned char
__mb_cur_max(void)413 __mb_cur_max(void)
414 {
415 return (__mb_cur_max_l(uselocale(NULL)));
416 }
417
418 /*
419 * Public interfaces.
420 */
421
422 locale_t
duplocale(locale_t src)423 duplocale(locale_t src)
424 {
425 locale_t loc;
426 int i;
427
428 loc = lmalloc(sizeof (*loc));
429 if (loc == NULL) {
430 return (NULL);
431 }
432 if (src == NULL) {
433 /* illumos extension: POSIX says LC_GLOBAL_LOCALE here */
434 src = ___global_locale;
435 }
436 for (i = 0; i < LC_ALL; i++) {
437 loc->locdata[i] = src->locdata[i];
438 loc->loaded[i] = 0;
439 }
440 loc->collate = loc->locdata[LC_COLLATE]->l_data[0];
441 loc->ctype = loc->locdata[LC_CTYPE]->l_data[0];
442 loc->runelocale = loc->locdata[LC_CTYPE]->l_data[1];
443 loc->messages = loc->locdata[LC_MESSAGES]->l_data[0];
444 loc->monetary = loc->locdata[LC_MONETARY]->l_data[0];
445 loc->numeric = loc->locdata[LC_NUMERIC]->l_data[0];
446 loc->time = loc->locdata[LC_TIME]->l_data[0];
447 return (loc);
448 }
449
450 void
freelocale(locale_t loc)451 freelocale(locale_t loc)
452 {
453 /*
454 * We take extra care never to free a saved locale created by
455 * setlocale(). This shouldn't be strictly necessary, but a little
456 * extra safety doesn't hurt here.
457 */
458 if ((loc != NULL) && (loc != &posix_locale) && (!loc->on_list))
459 lfree(loc, sizeof (*loc));
460 }
461
462 locale_t
newlocale(int catmask,const char * locname,locale_t base)463 newlocale(int catmask, const char *locname, locale_t base)
464 {
465 locale_t loc;
466 int i, e;
467
468 if (catmask & ~(LC_ALL_MASK)) {
469 errno = EINVAL;
470 return (NULL);
471 }
472
473 /*
474 * Technically passing LC_GLOBAL_LOCALE here is illegal,
475 * but we allow it.
476 */
477 if (base == NULL || base == ___global_locale) {
478 loc = duplocale(___global_locale);
479 } else {
480 loc = duplocale(base);
481 }
482 if (loc == NULL) {
483 return (NULL);
484 }
485
486 for (i = 0; i < LC_ALL; i++) {
487 struct locdata *ldata;
488 loc->loaded[i] = 0;
489 if (((1 << i) & catmask) == 0) {
490 /* Default to base locale if not overriding */
491 continue;
492 }
493 ldata = locdata_get(i, locname);
494 if (ldata == NULL) {
495 e = errno;
496 freelocale(loc);
497 errno = e;
498 return (NULL);
499 }
500 loc->locdata[i] = ldata;
501 }
502 loc->collate = loc->locdata[LC_COLLATE]->l_data[0];
503 loc->ctype = loc->locdata[LC_CTYPE]->l_data[0];
504 loc->runelocale = loc->locdata[LC_CTYPE]->l_data[1];
505 loc->messages = loc->locdata[LC_MESSAGES]->l_data[0];
506 loc->monetary = loc->locdata[LC_MONETARY]->l_data[0];
507 loc->numeric = loc->locdata[LC_NUMERIC]->l_data[0];
508 loc->time = loc->locdata[LC_TIME]->l_data[0];
509 freelocale(base);
510
511 return (mklocname(loc));
512 }
513
514 locale_t
uselocale(locale_t loc)515 uselocale(locale_t loc)
516 {
517 locale_t lastloc = ___global_locale;
518 locale_t *locptr;
519
520 locptr = tsdalloc(_T_SETLOCALE, sizeof (locale_t), freelocptr);
521 /* Should never occur */
522 if (locptr == NULL) {
523 errno = EINVAL;
524 return (NULL);
525 }
526
527 if (*locptr != NULL)
528 lastloc = *locptr;
529
530 /* Argument loc is NULL if we are just querying. */
531 if (loc != NULL) {
532 /*
533 * Set it to LC_GLOBAL_LOCAL to return to using
534 * the global locale (setlocale).
535 */
536 if (loc == ___global_locale) {
537 *locptr = NULL;
538 } else {
539 /* No validation of the provided locale at present */
540 *locptr = loc;
541 }
542 }
543
544 /*
545 * The caller is responsible for freeing, of course it would be
546 * gross error to call freelocale() on a locale object that is still
547 * in use.
548 */
549 return (lastloc);
550 }
551
552 static locale_t
mklocname(locale_t loc)553 mklocname(locale_t loc)
554 {
555 int composite = 0;
556
557 /* Look to see if any category is different */
558 for (int i = 1; i < LC_ALL; ++i) {
559 if (strcmp(loc->locdata[0]->l_lname,
560 loc->locdata[i]->l_lname) != 0) {
561 composite = 1;
562 break;
563 }
564 }
565
566 if (composite) {
567 /*
568 * Note ordering of these follows the numeric order,
569 * if the order is changed, then setlocale() will need
570 * to be changed as well.
571 */
572 (void) snprintf(loc->locname, sizeof (loc->locname),
573 "%s/%s/%s/%s/%s/%s",
574 loc->locdata[LC_CTYPE]->l_lname,
575 loc->locdata[LC_NUMERIC]->l_lname,
576 loc->locdata[LC_TIME]->l_lname,
577 loc->locdata[LC_COLLATE]->l_lname,
578 loc->locdata[LC_MONETARY]->l_lname,
579 loc->locdata[LC_MESSAGES]->l_lname);
580 } else {
581 (void) strlcpy(loc->locname, loc->locdata[LC_CTYPE]->l_lname,
582 sizeof (loc->locname));
583 }
584 return (loc);
585 }
586