xref: /titanic_41/usr/src/cmd/localedef/wide.c (revision 49d3bc91e27cd871b950d56c01398fa2f2e12ab4)
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 2011 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 	{ NULL, NULL },
120 };
121 
122 static char *
123 show_mb(const char *mb)
124 {
125 	static char buf[64];
126 
127 	/* ASCII stuff we just print */
128 	if (isascii(*mb) && isgraph(*mb)) {
129 		buf[0] = *mb;
130 		buf[1] = 0;
131 		return (buf);
132 	}
133 	buf[0] = 0;
134 	while (*mb != 0) {
135 		char scr[8];
136 		(void) snprintf(scr, sizeof (scr), "\\x%02x", *mb);
137 		(void) strlcat(buf, scr, sizeof (buf));
138 		mb++;
139 	}
140 	return (buf);
141 }
142 
143 static char	*widemsg;
144 
145 void
146 werr(const char *fmt, ...)
147 {
148 	char	*msg;
149 
150 	va_list	va;
151 	va_start(va, fmt);
152 	(void) vasprintf(&msg, fmt, va);
153 	va_end(va);
154 
155 	free(widemsg);
156 	widemsg = msg;
157 }
158 
159 /*
160  * This is used for 8-bit encodings.
161  */
162 int
163 towide_none(wchar_t *c, const char *mb, int n)
164 {
165 	if (mb_cur_max != 1) {
166 		werr("invalid or unsupported multibyte locale");
167 		return (-1);
168 	}
169 	if (n < 1) {
170 		werr("no character data");
171 		return (-1);
172 	}
173 	*c = (uint8_t)*mb;
174 	return (1);
175 }
176 
177 int
178 tomb_none(char *mb, wchar_t wc)
179 {
180 	if (mb_cur_max != 1) {
181 		werr("invalid or unsupported multibyte locale");
182 		return (-1);
183 	}
184 	*(uint8_t *)mb = (wc & 0xff);
185 	mb[1] = 0;
186 	return (1);
187 }
188 
189 /*
190  * UTF-8 stores wide characters in UTF-32 form.
191  */
192 int
193 towide_utf8(wchar_t *wc, const char *mb, int n)
194 {
195 	wchar_t	c;
196 	int	nb;
197 	int	lv;	/* lowest legal value */
198 	int	i;
199 	const uint8_t *s = (const uint8_t *)mb;
200 
201 	if (n < 1) {
202 		werr("no utf8 data");
203 		return (-1);
204 	}
205 	c = *s;
206 
207 	if ((c & 0x80) == 0) {
208 		/* 7-bit ASCII */
209 		*wc = c;
210 		return (1);
211 	} else if ((c & 0xe0) == 0xc0) {
212 		/* u80-u7ff - two bytes encoded */
213 		nb = 2;
214 		lv = 0x80;
215 		c &= ~0xe0;
216 	} else if ((c & 0xf0) == 0xe0) {
217 		/* u800-uffff - three bytes encoded */
218 		nb = 3;
219 		lv = 0x800;
220 		c &= ~0xf0;
221 	} else if ((c & 0xf8) == 0xf0) {
222 		/* u1000-u1fffff - four bytes encoded */
223 		nb = 4;
224 		lv = 0x1000;
225 		c &= ~0xf8;
226 	} else {
227 		/* 5 and 6 byte encodings are not legal unicode */
228 		werr("utf8 encoding too large (%s)", show_mb(mb));
229 		return (-1);
230 	}
231 	if (nb > n) {
232 		werr("incomplete utf8 sequence (%s)", show_mb(mb));
233 		return (-1);
234 	}
235 
236 	for (i = 1; i < nb; i++) {
237 		if (((s[i]) & 0xc0) != 0x80) {
238 			werr("illegal utf8 byte (%x)", s[i]);
239 			return (-1);
240 		}
241 		c <<= 6;
242 		c |= (s[i] & 0x3f);
243 	}
244 
245 	if (c < lv) {
246 		werr("illegal redundant utf8 encoding (%s)", show_mb(mb));
247 		return (-1);
248 	}
249 	*wc = c;
250 	return (nb);
251 }
252 
253 int
254 tomb_utf8(char *mb, wchar_t wc)
255 {
256 	uint8_t *s = (uint8_t *)mb;
257 	uint8_t msk;
258 	int cnt;
259 	int i;
260 
261 	if (wc <= 0x7f) {
262 		s[0] = wc & 0x7f;
263 		s[1] = 0;
264 		return (1);
265 	}
266 	if (wc <= 0x7ff) {
267 		cnt = 2;
268 		msk = 0xc0;
269 	} else if (wc <= 0xffff) {
270 		cnt = 3;
271 		msk = 0xe0;
272 	} else if (wc <= 0x1fffff) {
273 		cnt = 4;
274 		msk = 0xf0;
275 	} else {
276 		werr("illegal uf8 char (%x)", wc);
277 		return (-1);
278 	}
279 	for (i = cnt - 1; i; i--) {
280 		s[i] = (wc & 0x3f) | 0x80;
281 		wc >>= 6;
282 	}
283 	s[0] = (msk) | wc;
284 	s[cnt] = 0;
285 	return (cnt);
286 }
287 
288 /*
289  * Several encodings share a simplistic dual byte encoding.  In these
290  * forms, they all indicate that a two byte sequence is to be used if
291  * the first byte has its high bit set.  They all store this simple
292  * encoding as a 16-bit value, although a great many of the possible
293  * code points are not used in most character sets.  This gives a possible
294  * set of just over 32,000 valid code points.
295  *
296  * 0x00 - 0x7f		- 1 byte encoding
297  * 0x80 - 0x7fff	- illegal
298  * 0x8000 - 0xffff	- 2 byte encoding
299  */
300 static int
301 towide_dbcs(wchar_t *wc, const char *mb, int n)
302 {
303 	wchar_t	c;
304 
305 	c = *(uint8_t *)mb;
306 
307 	if (n < 1) {
308 		werr("no character data");
309 		return (-1);
310 	}
311 	if ((c & 0x80) == 0) {
312 		/* 7-bit */
313 		*wc = c;
314 		return (1);
315 	}
316 	if (n < 2) {
317 		werr("incomplete character sequence (%s)", show_mb(mb));
318 		return (-1);
319 	}
320 
321 	/* Store both bytes as a single 16-bit wide. */
322 	c <<= 8;
323 	c |= (uint8_t)(mb[1]);
324 	*wc = c;
325 	return (2);
326 }
327 
328 /*
329  * Most multibyte locales just convert the wide character to the multibyte
330  * form by stripping leading null bytes, and writing the 32-bit quantity
331  * in big-endian order.
332  */
333 int
334 tomb_mbs(char *mb, wchar_t wc)
335 {
336 	uint8_t *s = (uint8_t *)mb;
337 	int 	n = 0, c;
338 
339 	if ((wc & 0xff000000U) != 0) {
340 		n = 4;
341 	} else if ((wc & 0x00ff0000U) != 0) {
342 		n = 3;
343 	} else if ((wc & 0x0000ff00U) != 0) {
344 		n = 2;
345 	} else {
346 		n = 1;
347 	}
348 	c = n;
349 	while (n) {
350 		n--;
351 		s[n] = wc & 0xff;
352 		wc >>= 8;
353 	}
354 	/* ensure null termination */
355 	s[c] = 0;
356 	return (c);
357 }
358 
359 
360 /*
361  * big5 is a simple dual byte character set.
362  */
363 int
364 towide_big5(wchar_t *wc, const char *mb, int n)
365 {
366 	return (towide_dbcs(wc, mb, n));
367 }
368 
369 /*
370  * GBK encodes wides in the same way that big5 does, the high order
371  * bit of the first byte indicates a double byte character.
372  */
373 int
374 towide_gbk(wchar_t *wc, const char *mb, int n)
375 {
376 	return (towide_dbcs(wc, mb, n));
377 }
378 
379 /*
380  * GB2312 is another DBCS.  Its cleaner than others in that the second
381  * byte does not encode ASCII, but it supports characters.
382  */
383 int
384 towide_gb2312(wchar_t *wc, const char *mb, int n)
385 {
386 	return (towide_dbcs(wc, mb, n));
387 }
388 
389 /*
390  * GB18030.  This encodes as 8, 16, or 32-bits.
391  * 7-bit values are in 1 byte,  4 byte sequences are used when
392  * the second byte encodes 0x30-39 and all other sequences are 2 bytes.
393  */
394 int
395 towide_gb18030(wchar_t *wc, const char *mb, int n)
396 {
397 	wchar_t	c;
398 
399 	c = *(uint8_t *)mb;
400 
401 	if (n < 1) {
402 		werr("no character data");
403 		return (-1);
404 	}
405 	if ((c & 0x80) == 0) {
406 		/* 7-bit */
407 		*wc = c;
408 		return (1);
409 	}
410 	if (n < 2) {
411 		werr("incomplete character sequence (%s)", show_mb(mb));
412 		return (-1);
413 	}
414 
415 	/* pull in the second byte */
416 	c <<= 8;
417 	c |= (uint8_t)(mb[1]);
418 
419 	if (((c & 0xff) >= 0x30) && ((c & 0xff) <= 0x39)) {
420 		if (n < 4) {
421 			werr("incomplete 4-byte character sequence (%s)",
422 			    show_mb(mb));
423 			return (-1);
424 		}
425 		c <<= 8;
426 		c |= (uint8_t)(mb[2]);
427 		c <<= 8;
428 		c |= (uint8_t)(mb[3]);
429 		*wc = c;
430 		return (4);
431 	}
432 
433 	*wc = c;
434 	return (2);
435 }
436 
437 /*
438  * MS-Kanji (aka SJIS) is almost a clean DBCS like the others, but it
439  * also has a range of single byte characters above 0x80.  (0xa1-0xdf).
440  */
441 int
442 towide_mskanji(wchar_t *wc, const char *mb, int n)
443 {
444 	wchar_t	c;
445 
446 	c = *(uint8_t *)mb;
447 
448 	if (n < 1) {
449 		werr("no character data");
450 		return (-1);
451 	}
452 	if ((c < 0x80) || ((c > 0xa0) && (c < 0xe0))) {
453 		/* 7-bit */
454 		*wc = c;
455 		return (-1);
456 	}
457 
458 	if (n < 2) {
459 		werr("incomplete character sequence (%s)", show_mb(mb));
460 		return (-1);
461 	}
462 
463 	/* Store both bytes as a single 16-bit wide. */
464 	c <<= 8;
465 	c |= (uint8_t)(mb[1]);
466 	*wc = c;
467 	return (2);
468 }
469 
470 /*
471  * EUC forms.  EUC encodings are "variable".  FreeBSD carries some additional
472  * variable data to encode these, but we're going to treat each as independent
473  * instead.  Its the only way we can sensibly move forward.
474  *
475  * Note that the way in which the different EUC forms vary is how wide
476  * CS2 and CS3 are and what the first byte of them is.
477  */
478 static int
479 towide_euc_impl(wchar_t *wc, const char *mb, int n,
480     uint8_t cs2, uint8_t cs2width, uint8_t cs3, uint8_t cs3width)
481 {
482 	int i;
483 	int width;
484 	wchar_t	c;
485 
486 	c = *(uint8_t *)mb;
487 
488 	if (n < 1) {
489 		werr("no character data");
490 		return (-1);
491 	}
492 
493 	/*
494 	 * All variations of EUC encode 7-bit ASCII as one byte, and use
495 	 * additional bytes for more than that.
496 	 */
497 	if ((c & 0x80) == 0) {
498 		/* 7-bit */
499 		*wc = c;
500 		return (1);
501 	}
502 
503 	/*
504 	 * All EUC variants reserve 0xa1-0xff to identify CS1, which
505 	 * is always two bytes wide.  Note that unused CS will be zero,
506 	 * and that cannot be true because we know that the high order
507 	 * bit must be set.
508 	 */
509 	if (c >= 0xa1) {
510 		width = 2;
511 	} else if (c == cs2) {
512 		width = cs2width;
513 	} else if (c == cs3) {
514 		width = cs3width;
515 	}
516 
517 	if (n < width) {
518 		werr("incomplete character sequence (%s)", show_mb(mb));
519 		return (-1);
520 	}
521 
522 	for (i = 1; i < width; i++) {
523 		/* pull in the next byte */
524 		c <<= 8;
525 		c |= (uint8_t)(mb[i]);
526 	}
527 
528 	*wc = c;
529 	return (width);
530 }
531 
532 /*
533  * EUC-CN encodes as follows:
534  *
535  * Code set 0 (ASCII):				0x21-0x7E
536  * Code set 1 (CNS 11643-1992 Plane 1):		0xA1A1-0xFEFE
537  * Code set 2:					unused
538  * Code set 3:					unused
539  */
540 int
541 towide_euccn(wchar_t *wc, const char *mb, int n)
542 {
543 	return (towide_euc_impl(wc, mb, n, 0x8e, 4, 0, 0));
544 }
545 
546 /*
547  * EUC-JP encodes as follows:
548  *
549  * Code set 0 (ASCII or JIS X 0201-1976 Roman):	0x21-0x7E
550  * Code set 1 (JIS X 0208):			0xA1A1-0xFEFE
551  * Code set 2 (half-width katakana):		0x8EA1-0x8EDF
552  * Code set 3 (JIS X 0212-1990):		0x8FA1A1-0x8FFEFE
553  */
554 int
555 towide_eucjp(wchar_t *wc, const char *mb, int n)
556 {
557 	return (towide_euc_impl(wc, mb, n, 0x8e, 2, 0x8f, 3));
558 }
559 
560 /*
561  * EUC-KR encodes as follows:
562  *
563  * Code set 0 (ASCII or KS C 5636-1993):	0x21-0x7E
564  * Code set 1 (KS C 5601-1992):			0xA1A1-0xFEFE
565  * Code set 2:					unused
566  * Code set 3:					unused
567  */
568 int
569 towide_euckr(wchar_t *wc, const char *mb, int n)
570 {
571 	return (towide_euc_impl(wc, mb, n, 0, 0, 0, 0));
572 }
573 
574 /*
575  * EUC-TW encodes as follows:
576  *
577  * Code set 0 (ASCII):				0x21-0x7E
578  * Code set 1 (CNS 11643-1992 Plane 1):		0xA1A1-0xFEFE
579  * Code set 2 (CNS 11643-1992 Planes 1-16):	0x8EA1A1A1-0x8EB0FEFE
580  * Code set 3:					unused
581  */
582 int
583 towide_euctw(wchar_t *wc, const char *mb, int n)
584 {
585 	return (towide_euc_impl(wc, mb, n, 0x8e, 4, 0, 0));
586 }
587 
588 /*
589  * Public entry points.
590  */
591 
592 int
593 to_wide(wchar_t *wc, const char *mb)
594 {
595 	/* this won't fail hard */
596 	return (_towide(wc, mb, strlen(mb) + 1));
597 }
598 
599 int
600 to_mb(char *mb, wchar_t wc)
601 {
602 	int	rv;
603 
604 	if ((rv = _tomb(mb, wc)) < 0) {
605 		errf(widemsg);
606 		free(widemsg);
607 		widemsg = NULL;
608 	}
609 	return (rv);
610 }
611 
612 char *
613 to_mb_string(const wchar_t *wcs)
614 {
615 	char	*mbs;
616 	char	*ptr;
617 	int	len;
618 
619 	mbs = malloc((wcslen(wcs) * mb_cur_max) + 1);
620 	if (mbs == NULL) {
621 		errf("out of memory");
622 		return (NULL);
623 	}
624 	ptr = mbs;
625 	while (*wcs) {
626 		if ((len = to_mb(ptr, *wcs)) < 0) {
627 			INTERR;
628 			free(mbs);
629 			return (NULL);
630 		}
631 		wcs++;
632 		ptr += len;
633 	}
634 	*ptr = 0;
635 	return (mbs);
636 }
637 
638 void
639 set_wide_encoding(const char *encoding)
640 {
641 	int i;
642 
643 	_towide = towide_none;
644 	_tomb = tomb_none;
645 	_encoding = "NONE";
646 	_nbits = 8;
647 
648 	for (i = 0; mb_encodings[i].name; i++) {
649 		if (strcasecmp(encoding, mb_encodings[i].name) == 0) {
650 			_towide = mb_encodings[i].towide;
651 			_tomb = mb_encodings[i].tomb;
652 			_encoding = mb_encodings[i].cname;
653 			_nbits = mb_encodings[i].nbits;
654 			break;
655 		}
656 	}
657 }
658 
659 const char *
660 get_wide_encoding(void)
661 {
662 	return (_encoding);
663 }
664 
665 int
666 max_wide(void)
667 {
668 	return ((int)((1U << _nbits) - 1));
669 }
670