xref: /freebsd/lib/libc/locale/gb18030.c (revision 2f02600abfddfc4e9f20dd384a2e729b451e16bd)
1 /*-
2  * Copyright (c) 2002-2004 Tim J. Robbins
3  * All rights reserved.
4  *
5  * Copyright (c) 2011 The FreeBSD Foundation
6  * All rights reserved.
7  * Portions of this software were developed by David Chisnall
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 /*
32  * PRC National Standard GB 18030-2000 encoding of Chinese text.
33  *
34  * See gb18030(5) for details.
35  */
36 
37 #include <sys/param.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <errno.h>
41 #include <runetype.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <wchar.h>
45 #include "mblocal.h"
46 
47 static size_t	_GB18030_mbrtowc(wchar_t * __restrict, const char * __restrict,
48 		    size_t, mbstate_t * __restrict);
49 static int	_GB18030_mbsinit(const mbstate_t *);
50 static size_t	_GB18030_wcrtomb(char * __restrict, wchar_t,
51 		    mbstate_t * __restrict);
52 
53 typedef struct {
54 	int	count;
55 	u_char	bytes[4];
56 } _GB18030State;
57 
58 int
59 _GB18030_init(struct xlocale_ctype *l, _RuneLocale *rl)
60 {
61 
62 	l->__mbrtowc = _GB18030_mbrtowc;
63 	l->__wcrtomb = _GB18030_wcrtomb;
64 	l->__mbsinit = _GB18030_mbsinit;
65 	l->runes = rl;
66 	l->__mb_cur_max = 4;
67 	l->__mb_sb_limit = 128;
68 
69 	return (0);
70 }
71 
72 static int
73 _GB18030_mbsinit(const mbstate_t *ps)
74 {
75 
76 	return (ps == NULL || ((const _GB18030State *)ps)->count == 0);
77 }
78 
79 static size_t
80 _GB18030_mbrtowc(wchar_t * __restrict pwc, const char * __restrict s,
81     size_t n, mbstate_t * __restrict ps)
82 {
83 	_GB18030State *gs;
84 	wchar_t wch;
85 	int ch, len, ocount;
86 	size_t ncopy;
87 
88 	gs = (_GB18030State *)ps;
89 
90 	if (gs->count < 0 || gs->count > sizeof(gs->bytes)) {
91 		errno = EINVAL;
92 		return ((size_t)-1);
93 	}
94 
95 	if (s == NULL) {
96 		s = "";
97 		n = 1;
98 		pwc = NULL;
99 	}
100 
101 	ncopy = MIN(MIN(n, MB_CUR_MAX), sizeof(gs->bytes) - gs->count);
102 	memcpy(gs->bytes + gs->count, s, ncopy);
103 	ocount = gs->count;
104 	gs->count += ncopy;
105 	s = (char *)gs->bytes;
106 	n = gs->count;
107 
108 	if (n == 0)
109 		/* Incomplete multibyte sequence */
110 		return ((size_t)-2);
111 
112 	/*
113 	 * Single byte:		[00-7f]
114 	 * Two byte:		[81-fe][40-7e,80-fe]
115 	 * Four byte:		[81-fe][30-39][81-fe][30-39]
116 	 */
117 	ch = (unsigned char)*s++;
118 	if (ch <= 0x7f) {
119 		len = 1;
120 		wch = ch;
121 	} else if (ch >= 0x81 && ch <= 0xfe) {
122 		wch = ch;
123 		if (n < 2)
124 			return ((size_t)-2);
125 		ch = (unsigned char)*s++;
126 		if ((ch >= 0x40 && ch <= 0x7e) || (ch >= 0x80 && ch <= 0xfe)) {
127 			wch = (wch << 8) | ch;
128 			len = 2;
129 		} else if (ch >= 0x30 && ch <= 0x39) {
130 			/*
131 			 * Strip high bit off the wide character we will
132 			 * eventually output so that it is positive when
133 			 * cast to wint_t on 32-bit twos-complement machines.
134 			 */
135 			wch = ((wch & 0x7f) << 8) | ch;
136 			if (n < 3)
137 				return ((size_t)-2);
138 			ch = (unsigned char)*s++;
139 			if (ch < 0x81 || ch > 0xfe)
140 				goto ilseq;
141 			wch = (wch << 8) | ch;
142 			if (n < 4)
143 				return ((size_t)-2);
144 			ch = (unsigned char)*s++;
145 			if (ch < 0x30 || ch > 0x39)
146 				goto ilseq;
147 			wch = (wch << 8) | ch;
148 			len = 4;
149 		} else
150 			goto ilseq;
151 	} else
152 		goto ilseq;
153 
154 	if (pwc != NULL)
155 		*pwc = wch;
156 	gs->count = 0;
157 	return (wch == L'\0' ? 0 : len - ocount);
158 ilseq:
159 	errno = EILSEQ;
160 	return ((size_t)-1);
161 }
162 
163 static size_t
164 _GB18030_wcrtomb(char * __restrict s, wchar_t wc, mbstate_t * __restrict ps)
165 {
166 	_GB18030State *gs;
167 	size_t len;
168 	int c;
169 
170 	gs = (_GB18030State *)ps;
171 
172 	if (gs->count != 0) {
173 		errno = EINVAL;
174 		return ((size_t)-1);
175 	}
176 
177 	if (s == NULL)
178 		/* Reset to initial shift state (no-op) */
179 		return (1);
180 	if ((wc & ~0x7fffffff) != 0)
181 		goto ilseq;
182 	if (wc & 0x7f000000) {
183 		/* Replace high bit that mbrtowc() removed. */
184 		wc |= 0x80000000;
185 		c = (wc >> 24) & 0xff;
186 		if (c < 0x81 || c > 0xfe)
187 			goto ilseq;
188 		*s++ = c;
189 		c = (wc >> 16) & 0xff;
190 		if (c < 0x30 || c > 0x39)
191 			goto ilseq;
192 		*s++ = c;
193 		c = (wc >> 8) & 0xff;
194 		if (c < 0x81 || c > 0xfe)
195 			goto ilseq;
196 		*s++ = c;
197 		c = wc & 0xff;
198 		if (c < 0x30 || c > 0x39)
199 			goto ilseq;
200 		*s++ = c;
201 		len = 4;
202 	} else if (wc & 0x00ff0000)
203 		goto ilseq;
204 	else if (wc & 0x0000ff00) {
205 		c = (wc >> 8) & 0xff;
206 		if (c < 0x81 || c > 0xfe)
207 			goto ilseq;
208 		*s++ = c;
209 		c = wc & 0xff;
210 		if (c < 0x40 || c == 0x7f || c == 0xff)
211 			goto ilseq;
212 		*s++ = c;
213 		len = 2;
214 	} else if (wc <= 0x7f) {
215 		*s++ = wc;
216 		len = 1;
217 	} else
218 		goto ilseq;
219 
220 	return (len);
221 ilseq:
222 	errno = EILSEQ;
223 	return ((size_t)-1);
224 }
225