1 /* $NetBSD: unicode.c,v 1.3 2015/06/21 14:09:47 maxv Exp $ */
2
3 /*-
4 * Copyright (c) 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Dieter Baron.
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "rcsid.h"
33 __KERNEL_RCSID(0, "$NetBSD: unicode.c,v 1.3 2015/06/21 14:09:47 maxv Exp $");
34
35 #include <stddef.h>
36
37 #include "unicode.h"
38
39 size_t
utf8_to_utf16(uint16_t * dst,size_t dst_len,const char * src,size_t src_len,int flags,int * errp)40 utf8_to_utf16(uint16_t *dst, size_t dst_len,
41 const char *src, size_t src_len,
42 int flags, int *errp)
43 {
44 const unsigned char *s;
45 size_t spos, dpos;
46 int error;
47 uint16_t c;
48
49 #define IS_CONT(c) (((c)&0xc0) == 0x80)
50
51 error = 0;
52 s = (const unsigned char *)src;
53 spos = dpos = 0;
54 while (spos < src_len) {
55 if (s[spos] < 0x80) {
56 c = s[spos++];
57 } else if ((flags & UNICODE_UTF8_LATIN1_FALLBACK)
58 && (spos >= src_len || !IS_CONT(s[spos+1]))
59 && s[spos]>=0xa0) {
60 /* not valid UTF-8, assume ISO 8859-1 */
61 c = s[spos++];
62 } else if (s[spos] < 0xc0 || s[spos] >= 0xf5) {
63 /* continuation byte without lead byte
64 * or lead byte for codepoint above 0x10ffff */
65 error++;
66 spos++;
67 continue;
68 } else if (s[spos] < 0xe0) {
69 if (spos >= src_len || !IS_CONT(s[spos+1])) {
70 spos++;
71 error++;
72 continue;
73 }
74 c = ((s[spos] & 0x3f) << 6) | (s[spos+1] & 0x3f);
75 spos += 2;
76 if (c < 0x80) {
77 /* overlong encoding */
78 error++;
79 continue;
80 }
81 } else if (s[spos] < 0xf0) {
82 if (spos >= src_len-2 ||
83 !IS_CONT(s[spos+1]) || !IS_CONT(s[spos+2])) {
84 spos++;
85 error++;
86 continue;
87 }
88 c = ((s[spos] & 0x0f) << 12) | ((s[spos+1] & 0x3f) << 6)
89 | (s[spos+2] & 0x3f);
90 spos += 3;
91 if (c < 0x800 || (c & 0xdf00) == 0xd800 ) {
92 /* overlong encoding or encoded surrogate */
93 error++;
94 continue;
95 }
96 } else {
97 uint32_t cc;
98 /* UTF-16 surrogate pair */
99
100 if (spos >= src_len-3 || !IS_CONT(s[spos+1])
101 || !IS_CONT(s[spos+2]) || !IS_CONT(s[spos+3])) {
102 spos++;
103 error++;
104 continue;
105 }
106 cc = ((s[spos] & 0x03) << 18) | ((s[spos+1] & 0x3f) << 12)
107 | ((s[spos+2] & 0x3f) << 6) | (s[spos+3] & 0x3f);
108 spos += 4;
109 if (cc < 0x10000) {
110 /* overlong encoding */
111 error++;
112 continue;
113 }
114 if (dst && dpos < dst_len)
115 dst[dpos] = (0xd800 | ((cc-0x10000)>>10));
116 dpos++;
117 c = 0xdc00 | ((cc-0x10000) & 0x3ff);
118 }
119
120 if (dst && dpos < dst_len)
121 dst[dpos] = c;
122 dpos++;
123 }
124
125 if (errp)
126 *errp = error;
127 return dpos;
128 #undef IS_CONT
129 }
130
131
132 size_t
utf16_to_utf8(char * dst,size_t dst_len,const uint16_t * src,size_t src_len,int flags,int * errp)133 utf16_to_utf8(char *dst, size_t dst_len,
134 const uint16_t *src, size_t src_len,
135 int flags, int *errp)
136 {
137 size_t spos, dpos;
138 int error;
139
140 #define CHECK_LENGTH(l) (dpos > dst_len-(l) ? dst=NULL : NULL)
141 #define ADD_BYTE(b) (dst ? dst[dpos] = (b) : 0, dpos++)
142
143 error = 0;
144 dpos = 0;
145 for (spos = 0; spos < src_len; spos++) {
146 if (src[spos] < 0x80) {
147 CHECK_LENGTH(1);
148 ADD_BYTE(src[spos]);
149 } else if (src[spos] < 0x800) {
150 CHECK_LENGTH(2);
151 ADD_BYTE(0xc0 | (src[spos]>>6));
152 ADD_BYTE(0x80 | (src[spos] & 0x3f));
153 } else if(src[spos] >= 0xd800 && src[spos] < 0xe000) {
154 if ((src[spos] & 0xdc00) == 0xd800) {
155 uint32_t c;
156 /* first surrogate */
157 if (spos == src_len - 1 || (src[spos+1] & 0xdc00) != 0xdc00) {
158 /* no second surrogate present */
159 error++;
160 continue;
161 }
162 spos++;
163 CHECK_LENGTH(4);
164 c = (((src[spos-1]&0x3ff) << 10) | (src[spos]&0x3ff)) + 0x10000;
165 ADD_BYTE(0xf0 | (c>>18));
166 ADD_BYTE(0x80 | ((c>>12) & 0x3f));
167 ADD_BYTE(0x80 | ((c>>6) & 0x3f));
168 ADD_BYTE(0x80 | (c & 0x3f));
169 } else if ((src[spos] & 0xdc00) == 0xdc00) {
170 /* second surrogate without preceding first surrogate */
171 error++;
172 } else {
173 /* in surrogate pair range but none found */
174 error++;
175 }
176 } else {
177 CHECK_LENGTH(3);
178 ADD_BYTE(0xe0 | src[spos]>>12);
179 ADD_BYTE(0x80 | ((src[spos]>>6) & 0x3f));
180 ADD_BYTE(0x80 | (src[spos] & 0x3f));
181 }
182 }
183
184 if (errp)
185 *errp = error;
186 return dpos;
187 #undef ADD_BYTE
188 #undef CHECK_LENGTH
189 }
190