1 /*
2 * Copyright (C) 1999-2001 Free Software Foundation, Inc.
3 * This file is part of the GNU LIBICONV Library.
4 *
5 * The GNU LIBICONV Library is free software; you can redistribute it
6 * and/or modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * The GNU LIBICONV Library is distributed in the hope that it will be
11 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public
16 * License along with the GNU LIBICONV Library; see the file COPYING.LIB.
17 * If not, write to the Free Software Foundation, Inc., 51 Franklin Street,
18 * Fifth Floor, Boston, MA 02110-1301, USA.
19 */
20
21 /*
22 * ISO-2022-CN
23 */
24
25 /* Specification: RFC 1922 */
26
27 #define ESC 0x1b
28 #define SO 0x0e
29 #define SI 0x0f
30
31 /*
32 * The state is composed of one of the following values
33 */
34 #define STATE_ASCII 0
35 #define STATE_TWOBYTE 1
36 /*
37 * and one of the following values, << 8
38 */
39 #define STATE2_NONE 0
40 #define STATE2_DESIGNATED_GB2312 1
41 #define STATE2_DESIGNATED_CNS11643_1 2
42 /*
43 * and one of the following values, << 16
44 */
45 #define STATE3_NONE 0
46 #define STATE3_DESIGNATED_CNS11643_2 1
47
48 #define SPLIT_STATE \
49 unsigned int state1 = state & 0xff, state2 = (state >> 8) & 0xff, state3 = state >> 16
50 #define COMBINE_STATE \
51 state = (state3 << 16) | (state2 << 8) | state1
52
53 static int
iso2022_cn_mbtowc(conv_t conv,ucs4_t * pwc,const unsigned char * s,int n)54 iso2022_cn_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
55 {
56 state_t state = conv->istate;
57 SPLIT_STATE;
58 int count = 0;
59 unsigned char c;
60 for (;;) {
61 c = *s;
62 if (c == ESC) {
63 if (n < count+4)
64 goto none;
65 if (s[1] == '$') {
66 if (s[2] == ')') {
67 if (s[3] == 'A') {
68 state2 = STATE2_DESIGNATED_GB2312;
69 s += 4; count += 4;
70 if (n < count+1)
71 goto none;
72 continue;
73 }
74 if (s[3] == 'G') {
75 state2 = STATE2_DESIGNATED_CNS11643_1;
76 s += 4; count += 4;
77 if (n < count+1)
78 goto none;
79 continue;
80 }
81 }
82 if (s[2] == '*') {
83 if (s[3] == 'H') {
84 state3 = STATE3_DESIGNATED_CNS11643_2;
85 s += 4; count += 4;
86 if (n < count+1)
87 goto none;
88 continue;
89 }
90 }
91 }
92 if (s[1] == 'N') {
93 switch (state3) {
94 case STATE3_NONE:
95 return RET_ILSEQ;
96 case STATE3_DESIGNATED_CNS11643_2:
97 if (s[2] < 0x80 && s[3] < 0x80) {
98 int ret = cns11643_2_mbtowc(conv,pwc,s+2,2);
99 if (ret == RET_ILSEQ)
100 return RET_ILSEQ;
101 if (ret != 2) abort();
102 COMBINE_STATE;
103 conv->istate = state;
104 return count+4;
105 } else
106 return RET_ILSEQ;
107 default: abort();
108 }
109 }
110 return RET_ILSEQ;
111 }
112 if (c == SO) {
113 if (state2 != STATE2_DESIGNATED_GB2312 && state2 != STATE2_DESIGNATED_CNS11643_1)
114 return RET_ILSEQ;
115 state1 = STATE_TWOBYTE;
116 s++; count++;
117 if (n < count+1)
118 goto none;
119 continue;
120 }
121 if (c == SI) {
122 state1 = STATE_ASCII;
123 s++; count++;
124 if (n < count+1)
125 goto none;
126 continue;
127 }
128 break;
129 }
130 switch (state1) {
131 case STATE_ASCII:
132 if (c < 0x80) {
133 int ret = ascii_mbtowc(conv,pwc,s,1);
134 if (ret == RET_ILSEQ)
135 return RET_ILSEQ;
136 if (ret != 1) abort();
137 if (*pwc == 0x000a || *pwc == 0x000d) {
138 state2 = STATE2_NONE; state3 = STATE3_NONE;
139 }
140 COMBINE_STATE;
141 conv->istate = state;
142 return count+1;
143 } else
144 return RET_ILSEQ;
145 case STATE_TWOBYTE:
146 if (n < count+2)
147 goto none;
148 if (s[0] < 0x80 && s[1] < 0x80) {
149 int ret;
150 switch (state2) {
151 case STATE2_NONE:
152 return RET_ILSEQ;
153 case STATE2_DESIGNATED_GB2312:
154 ret = gb2312_mbtowc(conv,pwc,s,2); break;
155 case STATE2_DESIGNATED_CNS11643_1:
156 ret = cns11643_1_mbtowc(conv,pwc,s,2); break;
157 default: abort();
158 }
159 if (ret == RET_ILSEQ)
160 return RET_ILSEQ;
161 if (ret != 2) abort();
162 COMBINE_STATE;
163 conv->istate = state;
164 return count+2;
165 } else
166 return RET_ILSEQ;
167 default: abort();
168 }
169
170 none:
171 COMBINE_STATE;
172 conv->istate = state;
173 return RET_TOOFEW(count);
174 }
175
176 static int
iso2022_cn_wctomb(conv_t conv,unsigned char * r,ucs4_t wc,int n)177 iso2022_cn_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
178 {
179 state_t state = conv->ostate;
180 SPLIT_STATE;
181 unsigned char buf[3];
182 int ret;
183
184 /* There is no need to handle Unicode 3.1 tag characters and to look for
185 "zh-CN" or "zh-TW" tags, because GB2312 and CNS11643 are disjoint. */
186
187 /* Try ASCII. */
188 ret = ascii_wctomb(conv,buf,wc,1);
189 if (ret != RET_ILUNI) {
190 if (ret != 1) abort();
191 if (buf[0] < 0x80) {
192 int count = (state1 == STATE_ASCII ? 1 : 2);
193 if (n < count)
194 return RET_TOOSMALL;
195 if (state1 != STATE_ASCII) {
196 r[0] = SI;
197 r += 1;
198 state1 = STATE_ASCII;
199 }
200 r[0] = buf[0];
201 if (wc == 0x000a || wc == 0x000d) {
202 state2 = STATE2_NONE; state3 = STATE3_NONE;
203 }
204 COMBINE_STATE;
205 conv->ostate = state;
206 return count;
207 }
208 }
209
210 /* Try GB 2312-1980. */
211 ret = gb2312_wctomb(conv,buf,wc,2);
212 if (ret != RET_ILUNI) {
213 if (ret != 2) abort();
214 if (buf[0] < 0x80 && buf[1] < 0x80) {
215 int count = (state2 == STATE2_DESIGNATED_GB2312 ? 0 : 4) + (state1 == STATE_TWOBYTE ? 0 : 1) + 2;
216 if (n < count)
217 return RET_TOOSMALL;
218 if (state2 != STATE2_DESIGNATED_GB2312) {
219 r[0] = ESC;
220 r[1] = '$';
221 r[2] = ')';
222 r[3] = 'A';
223 r += 4;
224 state2 = STATE2_DESIGNATED_GB2312;
225 }
226 if (state1 != STATE_TWOBYTE) {
227 r[0] = SO;
228 r += 1;
229 state1 = STATE_TWOBYTE;
230 }
231 r[0] = buf[0];
232 r[1] = buf[1];
233 COMBINE_STATE;
234 conv->ostate = state;
235 return count;
236 }
237 }
238
239 ret = cns11643_wctomb(conv,buf,wc,3);
240 if (ret != RET_ILUNI) {
241 if (ret != 3) abort();
242
243 /* Try CNS 11643-1992 Plane 1. */
244 if (buf[0] == 1 && buf[1] < 0x80 && buf[2] < 0x80) {
245 int count = (state2 == STATE2_DESIGNATED_CNS11643_1 ? 0 : 4) + (state1 == STATE_TWOBYTE ? 0 : 1) + 2;
246 if (n < count)
247 return RET_TOOSMALL;
248 if (state2 != STATE2_DESIGNATED_CNS11643_1) {
249 r[0] = ESC;
250 r[1] = '$';
251 r[2] = ')';
252 r[3] = 'G';
253 r += 4;
254 state2 = STATE2_DESIGNATED_CNS11643_1;
255 }
256 if (state1 != STATE_TWOBYTE) {
257 r[0] = SO;
258 r += 1;
259 state1 = STATE_TWOBYTE;
260 }
261 r[0] = buf[1];
262 r[1] = buf[2];
263 COMBINE_STATE;
264 conv->ostate = state;
265 return count;
266 }
267
268 /* Try CNS 11643-1992 Plane 2. */
269 if (buf[0] == 2 && buf[1] < 0x80 && buf[2] < 0x80) {
270 int count = (state3 == STATE3_DESIGNATED_CNS11643_2 ? 0 : 4) + 4;
271 if (n < count)
272 return RET_TOOSMALL;
273 if (state3 != STATE3_DESIGNATED_CNS11643_2) {
274 r[0] = ESC;
275 r[1] = '$';
276 r[2] = '*';
277 r[3] = 'H';
278 r += 4;
279 state3 = STATE3_DESIGNATED_CNS11643_2;
280 }
281 r[0] = ESC;
282 r[1] = 'N';
283 r[2] = buf[1];
284 r[3] = buf[2];
285 COMBINE_STATE;
286 conv->ostate = state;
287 return count;
288 }
289 }
290
291 return RET_ILUNI;
292 }
293
294 static int
iso2022_cn_reset(conv_t conv,unsigned char * r,int n)295 iso2022_cn_reset (conv_t conv, unsigned char *r, int n)
296 {
297 state_t state = conv->ostate;
298 SPLIT_STATE;
299 (void)state2;
300 (void)state3;
301 if (state1 != STATE_ASCII) {
302 if (n < 1)
303 return RET_TOOSMALL;
304 r[0] = SI;
305 /* conv->ostate = 0; will be done by the caller */
306 return 1;
307 } else
308 return 0;
309 }
310
311 #undef COMBINE_STATE
312 #undef SPLIT_STATE
313 #undef STATE3_DESIGNATED_CNS11643_2
314 #undef STATE3_NONE
315 #undef STATE2_DESIGNATED_CNS11643_1
316 #undef STATE2_DESIGNATED_GB2312
317 #undef STATE2_NONE
318 #undef STATE_TWOBYTE
319 #undef STATE_ASCII
320