xref: /freebsd/sys/dev/hyperv/utilities/unicode.h (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1 /* $NetBSD: unicode.h,v 1.1.1.1 2007/03/06 00:10:39 dillo 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  * $FreeBSD$
32  */
33 
34 #include <sys/types.h>
35 
36 #define UNICODE_DECOMPOSE		0x01
37 #define UNICODE_PRECOMPOSE		0x02
38 #define UNICODE_UTF8_LATIN1_FALLBACK	0x03
39 
40 size_t utf8_to_utf16(uint16_t *, size_t, const char *, size_t, int, int *);
41 size_t utf16_to_utf8(char *, size_t, const uint16_t *, size_t, int, int *);
42 
43 size_t
44 utf8_to_utf16(uint16_t *dst, size_t dst_len,
45 	      const char *src, size_t src_len,
46 	      int flags, int *errp)
47 {
48     const unsigned char *s;
49     size_t spos, dpos;
50     int error;
51     uint16_t c;
52 
53 #define IS_CONT(c)	(((c)&0xc0) == 0x80)
54 
55     error = 0;
56     s = (const unsigned char *)src;
57     spos = dpos = 0;
58     while (spos<src_len) {
59 	if (s[spos] < 0x80)
60 	    c = s[spos++];
61 	else if ((flags & UNICODE_UTF8_LATIN1_FALLBACK)
62 		 && (spos >= src_len || !IS_CONT(s[spos+1]))
63 		 && s[spos]>=0xa0) {
64 	    /* not valid UTF-8, assume ISO 8859-1 */
65 	    c = s[spos++];
66 	}
67 	else if (s[spos] < 0xc0 || s[spos] >= 0xf5) {
68 	    /* continuation byte without lead byte
69 	       or lead byte for codepoint above 0x10ffff */
70 	    error++;
71 	    spos++;
72 	    continue;
73 	}
74 	else if (s[spos] < 0xe0) {
75 	    if (spos >= src_len || !IS_CONT(s[spos+1])) {
76 		spos++;
77 		error++;
78 		continue;
79 	    }
80 	    c = ((s[spos] & 0x3f) << 6) | (s[spos+1] & 0x3f);
81 	    spos += 2;
82 	    if (c < 0x80) {
83 		/* overlong encoding */
84 		error++;
85 		continue;
86 	    }
87 	}
88 	else if (s[spos] < 0xf0) {
89 	    if (spos >= src_len-2
90 		|| !IS_CONT(s[spos+1]) || !IS_CONT(s[spos+2])) {
91 		spos++;
92 		error++;
93 		continue;
94 	    }
95 	    c = ((s[spos] & 0x0f) << 12) | ((s[spos+1] & 0x3f) << 6)
96 		| (s[spos+2] & 0x3f);
97 	    spos += 3;
98 	    if (c < 0x800 || (c & 0xdf00) == 0xd800 ) {
99 		/* overlong encoding or encoded surrogate */
100 		error++;
101 		continue;
102 	    }
103 	}
104 	else {
105 	    uint32_t cc;
106 	    /* UTF-16 surrogate pair */
107 
108 	    if (spos >= src_len-3 || !IS_CONT(s[spos+1])
109 		|| !IS_CONT(s[spos+2]) || !IS_CONT(s[spos+3])) {
110 		spos++;
111 		error++;
112 
113 		continue;
114 	    }
115 	    cc = ((s[spos] & 0x03) << 18) | ((s[spos+1] & 0x3f) << 12)
116 		 | ((s[spos+2] & 0x3f) << 6) | (s[spos+3] & 0x3f);
117 	    spos += 4;
118 	    if (cc < 0x10000) {
119 		/* overlong encoding */
120 		error++;
121 		continue;
122 	    }
123 	    if (dst && dpos < dst_len)
124 		dst[dpos] = (0xd800 | ((cc-0x10000)>>10));
125 	    dpos++;
126 	    c = 0xdc00 | ((cc-0x10000) & 0x3ffff);
127 	}
128 
129 	if (dst && dpos < dst_len)
130 	    dst[dpos] = c;
131 	dpos++;
132     }
133 
134     if (errp)
135 	*errp = error;
136 
137     return dpos;
138 
139 #undef IS_CONT
140 }
141 
142 
143 size_t
144 utf16_to_utf8(char *dst, size_t dst_len,
145 	      const uint16_t *src, size_t src_len,
146 	      int flags, int *errp)
147 {
148     uint16_t spos, dpos;
149     int error;
150 
151 #define CHECK_LENGTH(l)	(dpos > dst_len-(l) ? dst=NULL : NULL)
152 #define ADD_BYTE(b)	(dst ? dst[dpos] = (b) : 0, dpos++)
153 
154     error = 0;
155     dpos = 0;
156     for (spos=0; spos<src_len; spos++) {
157 	if (src[spos] < 0x80) {
158 	    CHECK_LENGTH(1);
159 	    ADD_BYTE(src[spos]);
160 	}
161 	else if (src[spos] < 0x800) {
162 	    CHECK_LENGTH(2);
163 	    ADD_BYTE(0xc0 | (src[spos]>>6));
164 	    ADD_BYTE(0x80 | (src[spos] & 0x3f));
165 	}
166 	else if ((src[spos] & 0xdc00) == 0xd800) {
167 	    uint32_t c;
168 	    /* first surrogate */
169 	    if (spos == src_len - 1 || (src[spos] & 0xdc00) != 0xdc00) {
170 		/* no second surrogate present */
171 		error++;
172 		continue;
173 	    }
174 	    spos++;
175 	    CHECK_LENGTH(4);
176 	    c = (((src[spos]&0x3ff) << 10) | (src[spos+1]&0x3ff)) + 0x10000;
177 	    ADD_BYTE(0xf0 | (c>>18));
178 	    ADD_BYTE(0x80 | ((c>>12) & 0x3f));
179 	    ADD_BYTE(0x80 | ((c>>6) & 0x3f));
180 	    ADD_BYTE(0x80 | (c & 0x3f));
181 	}
182 	else if ((src[spos] & 0xdc00) == 0xdc00) {
183 	    /* second surrogate without preceding first surrogate */
184 	    error++;
185 	}
186 	else {
187 	    CHECK_LENGTH(3);
188 	    ADD_BYTE(0xe0 | src[spos]>>12);
189 	    ADD_BYTE(0x80 | ((src[spos]>>6) & 0x3f));
190 	    ADD_BYTE(0x80 | (src[spos] & 0x3f));
191 	}
192     }
193 
194     if (errp)
195 	*errp = error;
196 
197     return dpos;
198 
199 #undef ADD_BYTE
200 #undef CHECK_LENGTH
201 }
202