xref: /titanic_41/usr/src/cmd/localedef/wide.c (revision 5d4606d7857958f486a2dc8cb37c99a0b72335d6)
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 version 1.0
5  * 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 2010 Nexenta Systems, Inc.  All rights reserved.
14  */
15 
16 /*
17  * The functions in this file convert from the standard multibyte forms
18  * to the wide character forms used internally by libc.  Unfortunately,
19  * this approach means that we need a method for each and every encoding.
20  */
21 
22 #include <stdlib.h>
23 #include <wchar.h>
24 #include <string.h>
25 #include <sys/types.h>
26 #include "localedef.h"
27 
28 static int towide_none(wchar_t *, const char *, int);
29 static int towide_utf8(wchar_t *, const char *, int);
30 static int towide_big5(wchar_t *, const char *, int);
31 static int towide_gbk(wchar_t *, const char *, int);
32 static int towide_gb2312(wchar_t *, const char *, int);
33 static int towide_gb18030(wchar_t *, const char *, int);
34 static int towide_mskanji(wchar_t *, const char *, int);
35 static int towide_euccn(wchar_t *, const char *, int);
36 static int towide_eucjp(wchar_t *, const char *, int);
37 static int towide_euckr(wchar_t *, const char *, int);
38 static int towide_euctw(wchar_t *, const char *, int);
39 
40 static int tomb_none(char *, wchar_t);
41 static int tomb_utf8(char *, wchar_t);
42 static int tomb_mbs(char *, wchar_t);
43 
44 static int (*_towide)(wchar_t *, const char *, int) = towide_none;
45 static int (*_tomb)(char *, wchar_t) = tomb_none;
46 static const char *_encoding = "NONE";
47 static int _nbits = 7;
48 
49 /*
50  * Table of supported encodings.  We only bother to list the multibyte
51  * encodings here, because single byte locales are handed by "NONE".
52  */
53 static struct {
54 	const char *name;
55 	/* the name that the underlying libc implemenation uses */
56 	const char *cname;
57 	/* the maximum number of bits required for priorities */
58 	int nbits;
59 	int (*towide)(wchar_t *, const char *, int);
60 	int (*tomb)(char *, wchar_t);
61 } mb_encodings[] = {
62 	/*
63 	 * UTF8 values max out at 0x1fffff (although in theory there could
64 	 * be later extensions, but it won't happen.)  This means we only need
65 	 * 21 bits to be able to encode the entire range of priorities.
66 	 */
67 	{ "UTF-8",	"UTF-8",	21, towide_utf8, tomb_utf8 },
68 	{ "UTF8",	"UTF-8",	21, towide_utf8, tomb_utf8 },
69 	{ "utf8",	"UTF-8",	21, towide_utf8, tomb_utf8 },
70 	{ "utf-8",	"UTF-8",	21, towide_utf8, tomb_utf8 },
71 
72 	{ "EUC-CN",	"EUC-CN",	16, towide_euccn, tomb_mbs },
73 	{ "eucCN",	"EUC-CN",	16, towide_euccn, tomb_mbs },
74 	/*
75 	 * Becuase the 3-byte form of EUC-JP use the same leading byte,
76 	 * only 17 bits required to provide unique priorities.  (The low
77 	 * bit of that first byte is set.)  By setting this value low,
78 	 * we can get by with only 3 bytes in the strxfrm expansion.
79 	 */
80 	{ "EUC-JP",	"EUC-JP",	17, towide_eucjp, tomb_mbs },
81 	{ "eucJP",	"EUC-JP",	17, towide_eucjp, tomb_mbs },
82 
83 	{ "EUC-KR",	"EUC-KR",	16, towide_euckr, tomb_mbs },
84 	{ "eucKR",	"EUC-KR",	16, towide_euckr, tomb_mbs },
85 	/*
86 	 * EUC-TW uses 2 bytes most of the time, but 4 bytes if the
87 	 * high order byte is 0x8E.  However, with 4 byte encodings,
88 	 * the third byte will be A0-B0.  So we only need to consider
89 	 * the lower order 24 bits for collation.
90 	 */
91 	{ "EUC-TW",	"EUC-TW",	24, towide_euctw, tomb_mbs },
92 	{ "eucTW",	"EUC-TW",	24, towide_euctw, tomb_mbs },
93 
94 	{ "MS_Kanji",	"MSKanji",	16, towide_mskanji, tomb_mbs },
95 	{ "MSKanji",	"MSKanji",	16, towide_mskanji, tomb_mbs },
96 	{ "PCK",	"MSKanji",	16, towide_mskanji, tomb_mbs },
97 	{ "SJIS",	"MSKanji",	16, towide_mskanji, tomb_mbs },
98 	{ "Shift_JIS",	"MSKanji",	16, towide_mskanji, tomb_mbs },
99 
100 	{ "BIG5",	"BIG5",		16, towide_big5, tomb_mbs },
101 	{ "big5",	"BIG5",		16, towide_big5, tomb_mbs },
102 	{ "Big5",	"BIG5",		16, towide_big5, tomb_mbs },
103 
104 	{ "GBK",	"GBK",		16, towide_gbk,	tomb_mbs },
105 
106 	/*
107 	 * GB18030 can get away with just 31 bits.  This is because the
108 	 * high order bit is always set for 4 byte values, and the
109 	 * at least one of the other bits in that 4 byte value will
110 	 * be non-zero.
111 	 */
112 	{ "GB18030",	"GB18030",	31, towide_gb18030, tomb_mbs },
113 
114 	/*
115 	 * This should probably be an aliase for euc-cn, or vice versa.
116 	 */
117 	{ "GB2312",	"GB2312",	16, towide_gb2312, tomb_mbs },
118 
119 	{ "ASCII",	"ASCII",	7, towide_none,	tomb_none },
120 	{ "US-ASCII",	"ASCII",	7, towide_none,	tomb_none },
121 	{ "646",	"ASCII",	7, towide_none,	tomb_none },
122 
123 	{ NULL, NULL },
124 };
125 
126 static char *
127 show_mb(const char *mb)
128 {
129 	static char buf[64];
130 
131 	/* ASCII stuff we just print */
132 	if (isascii(*mb) && isgraph(*mb)) {
133 		buf[0] = *mb;
134 		buf[1] = 0;
135 		return (buf);
136 	}
137 	buf[0] = 0;
138 	while (*mb != 0) {
139 		char scr[8];
140 		(void) snprintf(scr, sizeof (scr), "\\x%02x", *mb);
141 		(void) strlcat(buf, scr, sizeof (buf));
142 		mb++;
143 	}
144 	return (buf);
145 }
146 
147 static char	*widemsg;
148 
149 void
150 werr(const char *fmt, ...)
151 {
152 	char	*msg;
153 
154 	va_list	va;
155 	va_start(va, fmt);
156 	(void) vasprintf(&msg, fmt, va);
157 	va_end(va);
158 
159 	free(widemsg);
160 	widemsg = msg;
161 }
162 
163 /*
164  * This is used for 8-bit encodings.
165  */
166 int
167 towide_none(wchar_t *c, const char *mb, int n)
168 {
169 	if (mb_cur_max != 1) {
170 		werr("invalid or unsupported multibyte locale");
171 		return (-1);
172 	}
173 	if (n < 1) {
174 		werr("no character data");
175 		return (-1);
176 	}
177 	*c = (uint8_t)*mb;
178 	return (1);
179 }
180 
181 int
182 tomb_none(char *mb, wchar_t wc)
183 {
184 	if (mb_cur_max != 1) {
185 		werr("invalid or unsupported multibyte locale");
186 		return (-1);
187 	}
188 	*(uint8_t *)mb = (wc & 0xff);
189 	mb[1] = 0;
190 	return (1);
191 }
192 
193 /*
194  * UTF-8 stores wide characters in UTF-32 form.
195  */
196 int
197 towide_utf8(wchar_t *wc, const char *mb, int n)
198 {
199 	wchar_t	c;
200 	int	nb;
201 	int	lv;	/* lowest legal value */
202 	int	i;
203 	const uint8_t *s = (const uint8_t *)mb;
204 
205 	if (n < 1) {
206 		werr("no utf8 data");
207 		return (-1);
208 	}
209 	c = *s;
210 
211 	if ((c & 0x80) == 0) {
212 		/* 7-bit ASCII */
213 		*wc = c;
214 		return (1);
215 	} else if ((c & 0xe0) == 0xc0) {
216 		/* u80-u7ff - two bytes encoded */
217 		nb = 2;
218 		lv = 0x80;
219 		c &= ~0xe0;
220 	} else if ((c & 0xf0) == 0xe0) {
221 		/* u800-uffff - three bytes encoded */
222 		nb = 3;
223 		lv = 0x800;
224 		c &= ~0xf0;
225 	} else if ((c & 0xf8) == 0xf0) {
226 		/* u1000-u1fffff - four bytes encoded */
227 		nb = 4;
228 		lv = 0x1000;
229 		c &= ~0xf8;
230 	} else {
231 		/* 5 and 6 byte encodings are not legal unicode */
232 		werr("utf8 encoding too large (%s)", show_mb(mb));
233 		return (-1);
234 	}
235 	if (nb > n) {
236 		werr("incomplete utf8 sequence (%s)", show_mb(mb));
237 		return (-1);
238 	}
239 
240 	for (i = 1; i < nb; i++) {
241 		if (((s[i]) & 0xc0) != 0x80) {
242 			werr("illegal utf8 byte (%x)", s[i]);
243 			return (-1);
244 		}
245 		c <<= 6;
246 		c |= (s[i] & 0x3f);
247 	}
248 
249 	if (c < lv) {
250 		werr("illegal redundant utf8 encoding (%s)", show_mb(mb));
251 		return (-1);
252 	}
253 	*wc = c;
254 	return (nb);
255 }
256 
257 int
258 tomb_utf8(char *mb, wchar_t wc)
259 {
260 	uint8_t *s = (uint8_t *)mb;
261 	uint8_t msk;
262 	int cnt;
263 	int i;
264 
265 	if (wc <= 0x7f) {
266 		s[0] = wc & 0x7f;
267 		s[1] = 0;
268 		return (1);
269 	}
270 	if (wc <= 0x7ff) {
271 		cnt = 2;
272 		msk = 0xc0;
273 	} else if (wc <= 0xffff) {
274 		cnt = 3;
275 		msk = 0xe0;
276 	} else if (wc <= 0x1fffff) {
277 		cnt = 4;
278 		msk = 0xf0;
279 	} else {
280 		werr("illegal uf8 char (%x)", wc);
281 		return (-1);
282 	}
283 	for (i = cnt - 1; i; i--) {
284 		s[i] = (wc & 0x3f) | 0x80;
285 		wc >>= 6;
286 	}
287 	s[0] = (msk) | wc;
288 	s[cnt] = 0;
289 	return (cnt);
290 }
291 
292 /*
293  * Several encodings share a simplistic dual byte encoding.  In these
294  * forms, they all indicate that a two byte sequence is to be used if
295  * the first byte has its high bit set.  They all store this simple
296  * encoding as a 16-bit value, although a great many of the possible
297  * code points are not used in most character sets.  This gives a possible
298  * set of just over 32,000 valid code points.
299  *
300  * 0x00 - 0x7f		- 1 byte encoding
301  * 0x80 - 0x7fff	- illegal
302  * 0x8000 - 0xffff	- 2 byte encoding
303  */
304 static int
305 towide_dbcs(wchar_t *wc, const char *mb, int n)
306 {
307 	wchar_t	c;
308 
309 	c = *(uint8_t *)mb;
310 
311 	if (n < 1) {
312 		werr("no character data");
313 		return (-1);
314 	}
315 	if ((c & 0x80) == 0) {
316 		/* 7-bit */
317 		*wc = c;
318 		return (1);
319 	}
320 	if (n < 2) {
321 		werr("incomplete character sequence (%s)", show_mb(mb));
322 		return (-1);
323 	}
324 
325 	/* Store both bytes as a single 16-bit wide. */
326 	c <<= 8;
327 	c |= (uint8_t)(mb[1]);
328 	*wc = c;
329 	return (2);
330 }
331 
332 /*
333  * Most multibyte locales just convert the wide character to the multibyte
334  * form by stripping leading null bytes, and writing the 32-bit quantity
335  * in big-endian order.
336  */
337 int
338 tomb_mbs(char *mb, wchar_t wc)
339 {
340 	uint8_t *s = (uint8_t *)mb;
341 	int 	n = 0, c;
342 
343 	if ((wc & 0xff000000U) != 0) {
344 		n = 4;
345 	} else if ((wc & 0x00ff0000U) != 0) {
346 		n = 3;
347 	} else if ((wc & 0x0000ff00U) != 0) {
348 		n = 2;
349 	} else {
350 		n = 1;
351 	}
352 	c = n;
353 	while (n) {
354 		n--;
355 		s[n] = wc & 0xff;
356 		wc >>= 8;
357 	}
358 	/* ensure null termination */
359 	s[c] = 0;
360 	return (c);
361 }
362 
363 
364 /*
365  * big5 is a simple dual byte character set.
366  */
367 int
368 towide_big5(wchar_t *wc, const char *mb, int n)
369 {
370 	return (towide_dbcs(wc, mb, n));
371 }
372 
373 /*
374  * GBK encodes wides in the same way that big5 does, the high order
375  * bit of the first byte indicates a double byte character.
376  */
377 int
378 towide_gbk(wchar_t *wc, const char *mb, int n)
379 {
380 	return (towide_dbcs(wc, mb, n));
381 }
382 
383 /*
384  * GB2312 is another DBCS.  Its cleaner than others in that the second
385  * byte does not encode ASCII, but it supports characters.
386  */
387 int
388 towide_gb2312(wchar_t *wc, const char *mb, int n)
389 {
390 	return (towide_dbcs(wc, mb, n));
391 }
392 
393 /*
394  * GB18030.  This encodes as 8, 16, or 32-bits.
395  * 7-bit values are in 1 byte,  4 byte sequences are used when
396  * the second byte encodes 0x30-39 and all other sequences are 2 bytes.
397  */
398 int
399 towide_gb18030(wchar_t *wc, const char *mb, int n)
400 {
401 	wchar_t	c;
402 
403 	c = *(uint8_t *)mb;
404 
405 	if (n < 1) {
406 		werr("no character data");
407 		return (-1);
408 	}
409 	if ((c & 0x80) == 0) {
410 		/* 7-bit */
411 		*wc = c;
412 		return (1);
413 	}
414 	if (n < 2) {
415 		werr("incomplete character sequence (%s)", show_mb(mb));
416 		return (-1);
417 	}
418 
419 	/* pull in the second byte */
420 	c <<= 8;
421 	c |= (uint8_t)(mb[1]);
422 
423 	if (((c & 0xff) >= 0x30) && ((c & 0xff) <= 0x39)) {
424 		if (n < 4) {
425 			werr("incomplete 4-byte character sequence (%s)",
426 			    show_mb(mb));
427 			return (-1);
428 		}
429 		c <<= 8;
430 		c |= (uint8_t)(mb[2]);
431 		c <<= 8;
432 		c |= (uint8_t)(mb[3]);
433 		*wc = c;
434 		return (4);
435 	}
436 
437 	*wc = c;
438 	return (2);
439 }
440 
441 /*
442  * MS-Kanji (aka SJIS) is almost a clean DBCS like the others, but it
443  * also has a range of single byte characters above 0x80.  (0xa1-0xdf).
444  */
445 int
446 towide_mskanji(wchar_t *wc, const char *mb, int n)
447 {
448 	wchar_t	c;
449 
450 	c = *(uint8_t *)mb;
451 
452 	if (n < 1) {
453 		werr("no character data");
454 		return (-1);
455 	}
456 	if ((c < 0x80) || ((c > 0xa0) && (c < 0xe0))) {
457 		/* 7-bit */
458 		*wc = c;
459 		return (-1);
460 	}
461 
462 	if (n < 2) {
463 		werr("incomplete character sequence (%s)", show_mb(mb));
464 		return (-1);
465 	}
466 
467 	/* Store both bytes as a single 16-bit wide. */
468 	c <<= 8;
469 	c |= (uint8_t)(mb[1]);
470 	*wc = c;
471 	return (2);
472 }
473 
474 /*
475  * EUC forms.  EUC encodings are "variable".  FreeBSD carries some additional
476  * variable data to encode these, but we're going to treat each as independent
477  * instead.  Its the only way we can sensibly move forward.
478  *
479  * Note that the way in which the different EUC forms vary is how wide
480  * CS2 and CS3 are and what the first byte of them is.
481  */
482 static int
483 towide_euc_impl(wchar_t *wc, const char *mb, int n,
484     uint8_t cs2, uint8_t cs2width, uint8_t cs3, uint8_t cs3width)
485 {
486 	int i;
487 	int width;
488 	wchar_t	c;
489 
490 	c = *(uint8_t *)mb;
491 
492 	if (n < 1) {
493 		werr("no character data");
494 		return (-1);
495 	}
496 
497 	/*
498 	 * All variations of EUC encode 7-bit ASCII as one byte, and use
499 	 * additional bytes for more than that.
500 	 */
501 	if ((c & 0x80) == 0) {
502 		/* 7-bit */
503 		*wc = c;
504 		return (1);
505 	}
506 
507 	/*
508 	 * All EUC variants reserve 0xa1-0xff to identify CS1, which
509 	 * is always two bytes wide.  Note that unused CS will be zero,
510 	 * and that cannot be true because we know that the high order
511 	 * bit must be set.
512 	 */
513 	if (c >= 0xa1) {
514 		width = 2;
515 	} else if (c == cs2) {
516 		width = cs2width;
517 	} else if (c == cs3) {
518 		width = cs3width;
519 	}
520 
521 	if (n < width) {
522 		werr("incomplete character sequence (%s)", show_mb(mb));
523 		return (-1);
524 	}
525 
526 	for (i = 1; i < width; i++) {
527 		/* pull in the next byte */
528 		c <<= 8;
529 		c |= (uint8_t)(mb[i]);
530 	}
531 
532 	*wc = c;
533 	return (width);
534 }
535 
536 /*
537  * EUC-CN encodes as follows:
538  *
539  * Code set 0 (ASCII):				0x21-0x7E
540  * Code set 1 (CNS 11643-1992 Plane 1):		0xA1A1-0xFEFE
541  * Code set 2:					unused
542  * Code set 3:					unused
543  */
544 int
545 towide_euccn(wchar_t *wc, const char *mb, int n)
546 {
547 	return (towide_euc_impl(wc, mb, n, 0x8e, 4, 0, 0));
548 }
549 
550 /*
551  * EUC-JP encodes as follows:
552  *
553  * Code set 0 (ASCII or JIS X 0201-1976 Roman):	0x21-0x7E
554  * Code set 1 (JIS X 0208):			0xA1A1-0xFEFE
555  * Code set 2 (half-width katakana):		0x8EA1-0x8EDF
556  * Code set 3 (JIS X 0212-1990):		0x8FA1A1-0x8FFEFE
557  */
558 int
559 towide_eucjp(wchar_t *wc, const char *mb, int n)
560 {
561 	return (towide_euc_impl(wc, mb, n, 0x8e, 2, 0x8f, 3));
562 }
563 
564 /*
565  * EUC-KR encodes as follows:
566  *
567  * Code set 0 (ASCII or KS C 5636-1993):	0x21-0x7E
568  * Code set 1 (KS C 5601-1992):			0xA1A1-0xFEFE
569  * Code set 2:					unused
570  * Code set 3:					unused
571  */
572 int
573 towide_euckr(wchar_t *wc, const char *mb, int n)
574 {
575 	return (towide_euc_impl(wc, mb, n, 0, 0, 0, 0));
576 }
577 
578 /*
579  * EUC-TW encodes as follows:
580  *
581  * Code set 0 (ASCII):				0x21-0x7E
582  * Code set 1 (CNS 11643-1992 Plane 1):		0xA1A1-0xFEFE
583  * Code set 2 (CNS 11643-1992 Planes 1-16):	0x8EA1A1A1-0x8EB0FEFE
584  * Code set 3:					unused
585  */
586 int
587 towide_euctw(wchar_t *wc, const char *mb, int n)
588 {
589 	return (towide_euc_impl(wc, mb, n, 0x8e, 4, 0, 0));
590 }
591 
592 /*
593  * Public entry points.
594  */
595 
596 int
597 to_wide(wchar_t *wc, const char *mb)
598 {
599 	/* this won't fail hard */
600 	return (_towide(wc, mb, strlen(mb) + 1));
601 }
602 
603 int
604 to_mb(char *mb, wchar_t wc)
605 {
606 	int	rv;
607 
608 	if ((rv = _tomb(mb, wc)) < 0) {
609 		errf(widemsg);
610 		free(widemsg);
611 		widemsg = NULL;
612 	}
613 	return (rv);
614 }
615 
616 char *
617 to_mb_string(const wchar_t *wcs)
618 {
619 	char	*mbs;
620 	char	*ptr;
621 	int	len;
622 
623 	mbs = malloc((wcslen(wcs) * mb_cur_max) + 1);
624 	if (mbs == NULL) {
625 		errf("out of memory");
626 		return (NULL);
627 	}
628 	ptr = mbs;
629 	while (*wcs) {
630 		if ((len = to_mb(ptr, *wcs)) < 0) {
631 			INTERR;
632 			free(mbs);
633 			return (NULL);
634 		}
635 		wcs++;
636 		ptr += len;
637 	}
638 	*ptr = 0;
639 	return (mbs);
640 }
641 
642 void
643 set_wide_encoding(const char *encoding)
644 {
645 	int i;
646 
647 	_towide = towide_none;
648 	_tomb = tomb_none;
649 	_encoding = "NONE";
650 	_nbits = 8;
651 
652 	for (i = 0; mb_encodings[i].name; i++) {
653 		if (strcasecmp(encoding, mb_encodings[i].name) == 0) {
654 			_towide = mb_encodings[i].towide;
655 			_tomb = mb_encodings[i].tomb;
656 			_encoding = mb_encodings[i].cname;
657 			_nbits = mb_encodings[i].nbits;
658 			break;
659 		}
660 	}
661 }
662 
663 const char *
664 get_wide_encoding(void)
665 {
666 	return (_encoding);
667 }
668 
669 int
670 max_wide(void)
671 {
672 	return ((int)((1U << _nbits) - 1));
673 }
674