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-KR
23 */
24
25 /* Specification: RFC 1557 */
26
27 /* Note: CJK.INF says the SO designator needs to appear only once at the
28 beginning of a text, but to decrease the risk of ambiguities, when
29 producing ISO-2022-KR, we repeat the designator in every line containing
30 SO characters. RFC 1557 does not mandate this. */
31
32 #define ESC 0x1b
33 #define SO 0x0e
34 #define SI 0x0f
35
36 /*
37 * The state is composed of one of the following values
38 */
39 #define STATE_ASCII 0
40 #define STATE_TWOBYTE 1
41 /*
42 * and one of the following values, << 8
43 */
44 #define STATE2_NONE 0
45 #define STATE2_DESIGNATED_KSC5601 1
46
47 #define SPLIT_STATE \
48 unsigned int state1 = state & 0xff, state2 = state >> 8
49 #define COMBINE_STATE \
50 state = (state2 << 8) | state1
51
52 static int
iso2022_kr_mbtowc(conv_t conv,ucs4_t * pwc,const unsigned char * s,int n)53 iso2022_kr_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
54 {
55 state_t state = conv->istate;
56 SPLIT_STATE;
57 int count = 0;
58 unsigned char c;
59 for (;;) {
60 c = *s;
61 if (c == ESC) {
62 if (n < count+4)
63 goto none;
64 if (s[1] == '$') {
65 if (s[2] == ')') {
66 if (s[3] == 'C') {
67 state2 = STATE2_DESIGNATED_KSC5601;
68 s += 4; count += 4;
69 if (n < count+1)
70 goto none;
71 continue;
72 }
73 }
74 }
75 return RET_ILSEQ;
76 }
77 if (c == SO) {
78 if (state2 != STATE2_DESIGNATED_KSC5601)
79 return RET_ILSEQ;
80 state1 = STATE_TWOBYTE;
81 s++; count++;
82 if (n < count+1)
83 goto none;
84 continue;
85 }
86 if (c == SI) {
87 state1 = STATE_ASCII;
88 s++; count++;
89 if (n < count+1)
90 goto none;
91 continue;
92 }
93 break;
94 }
95 switch (state1) {
96 case STATE_ASCII:
97 if (c < 0x80) {
98 int ret = ascii_mbtowc(conv,pwc,s,1);
99 if (ret == RET_ILSEQ)
100 return RET_ILSEQ;
101 if (ret != 1) abort();
102 #if 0 /* Accept ISO-2022-KR according to CJK.INF. */
103 if (*pwc == 0x000a || *pwc == 0x000d)
104 state2 = STATE2_NONE;
105 #endif
106 COMBINE_STATE;
107 conv->istate = state;
108 return count+1;
109 } else
110 return RET_ILSEQ;
111 case STATE_TWOBYTE:
112 if (n < count+2)
113 goto none;
114 if (state2 != STATE2_DESIGNATED_KSC5601) abort();
115 if (s[0] < 0x80 && s[1] < 0x80) {
116 int ret = ksc5601_mbtowc(conv,pwc,s,2);
117 if (ret == RET_ILSEQ)
118 return RET_ILSEQ;
119 if (ret != 2) abort();
120 COMBINE_STATE;
121 conv->istate = state;
122 return count+2;
123 } else
124 return RET_ILSEQ;
125 default: abort();
126 }
127
128 none:
129 COMBINE_STATE;
130 conv->istate = state;
131 return RET_TOOFEW(count);
132 }
133
134 static int
iso2022_kr_wctomb(conv_t conv,unsigned char * r,ucs4_t wc,int n)135 iso2022_kr_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
136 {
137 state_t state = conv->ostate;
138 SPLIT_STATE;
139 unsigned char buf[2];
140 int ret;
141
142 /* Try ASCII. */
143 ret = ascii_wctomb(conv,buf,wc,1);
144 if (ret != RET_ILUNI) {
145 if (ret != 1) abort();
146 if (buf[0] < 0x80) {
147 int count = (state1 == STATE_ASCII ? 1 : 2);
148 if (n < count)
149 return RET_TOOSMALL;
150 if (state1 != STATE_ASCII) {
151 r[0] = SI;
152 r += 1;
153 state1 = STATE_ASCII;
154 }
155 r[0] = buf[0];
156 if (wc == 0x000a || wc == 0x000d)
157 state2 = STATE2_NONE;
158 COMBINE_STATE;
159 conv->ostate = state;
160 return count;
161 }
162 }
163
164 /* Try KS C 5601-1992. */
165 ret = ksc5601_wctomb(conv,buf,wc,2);
166 if (ret != RET_ILUNI) {
167 if (ret != 2) abort();
168 if (buf[0] < 0x80 && buf[1] < 0x80) {
169 int count = (state2 == STATE2_DESIGNATED_KSC5601 ? 0 : 4) + (state1 == STATE_TWOBYTE ? 0 : 1) + 2;
170 if (n < count)
171 return RET_TOOSMALL;
172 if (state2 != STATE2_DESIGNATED_KSC5601) {
173 r[0] = ESC;
174 r[1] = '$';
175 r[2] = ')';
176 r[3] = 'C';
177 r += 4;
178 state2 = STATE2_DESIGNATED_KSC5601;
179 }
180 if (state1 != STATE_TWOBYTE) {
181 r[0] = SO;
182 r += 1;
183 state1 = STATE_TWOBYTE;
184 }
185 r[0] = buf[0];
186 r[1] = buf[1];
187 COMBINE_STATE;
188 conv->ostate = state;
189 return count;
190 }
191 }
192
193 return RET_ILUNI;
194 }
195
196 static int
iso2022_kr_reset(conv_t conv,unsigned char * r,int n)197 iso2022_kr_reset (conv_t conv, unsigned char *r, int n)
198 {
199 state_t state = conv->ostate;
200 SPLIT_STATE;
201 (void)state2;
202 if (state1 != STATE_ASCII) {
203 if (n < 1)
204 return RET_TOOSMALL;
205 r[0] = SI;
206 /* conv->ostate = 0; will be done by the caller */
207 return 1;
208 } else
209 return 0;
210 }
211
212 #undef COMBINE_STATE
213 #undef SPLIT_STATE
214 #undef STATE2_DESIGNATED_KSC5601
215 #undef STATE2_NONE
216 #undef STATE_TWOBYTE
217 #undef STATE_ASCII
218