xref: /openbsd/sys/ntfs/ntfs_conv.c (revision 73471bf0)
1 /*	$OpenBSD: ntfs_conv.c,v 1.9 2013/11/24 16:02:30 jsing Exp $	*/
2 /*	$NetBSD: ntfs_conv.c,v 1.1 2002/12/23 17:38:32 jdolecek Exp $	*/
3 
4 /*-
5  * Copyright (c) 2001 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 /*
31  * File name recode stuff.
32  *
33  * The utf-8 routines were derived from src/lib/libc/locale/utf2.c.
34  */
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/namei.h>
39 #include <sys/mount.h>
40 
41 /* #define NTFS_DEBUG 1 */
42 #include <ntfs/ntfs.h>
43 #include <ntfs/ntfs_inode.h>
44 #include <ntfs/ntfs_subr.h>
45 
46 /* UTF-8 encoding stuff */
47 
48 static const int _utf_count[16] = {
49         1, 1, 1, 1, 1, 1, 1, 1,
50         0, 0, 0, 0, 2, 2, 3, 0,
51 };
52 
53 /*
54  * Read one wide character off the string, shift the string pointer
55  * and return the character.
56  */
57 wchar
58 ntfs_utf8_wget(const char **str)
59 {
60 	int c;
61 	wchar rune = 0;
62 	const char *s = *str;
63 
64 	c = _utf_count[(s[0] >> 4) & 0xf];
65 	if (c == 0) {
66 		c = 1;
67 		goto encoding_error;
68 	}
69 
70 	switch (c) {
71 	case 1:
72 		rune = s[0] & 0xff;
73 		break;
74 	case 2:
75 		if ((s[1] & 0xc0) != 0x80)
76 			goto encoding_error;
77 		rune = ((s[0] & 0x1F) << 6) | (s[1] & 0x3F);
78 		break;
79 	case 3:
80 		if ((s[1] & 0xC0) != 0x80 || (s[2] & 0xC0) != 0x80)
81 			goto encoding_error;
82 		rune = ((s[0] & 0x1F) << 12) | ((s[1] & 0x3F) << 6) |
83 		    (s[2] & 0x3F);
84 		break;
85 	}
86 
87 encoding_error:
88 	*str = *str + c;
89 	return rune;
90 }
91 
92 /*
93  * Encode wide character and write it to the string. 'n' specifies
94  * how much space there is in the string. Returns number of bytes written
95  * to the target string.
96  */
97 int
98 ntfs_utf8_wput(char *s, size_t n, wchar wc)
99 {
100         if (wc & 0xf800) {
101                 if (n < 3) {
102                         /* bound check failure */
103 			DDPRINTF("ntfs_utf8_wput: need 3 bytes\n");
104                         return 0;
105                 }
106 
107                 s[0] = 0xE0 | ((wc >> 12) & 0x0F);
108                 s[1] = 0x80 | ((wc >> 6) & 0x3F);
109                 s[2] = 0x80 | ((wc) & 0x3F);
110                 return 3;
111         } else {
112                 if (wc & 0x0780) {
113                         if (n < 2) {
114                                 /* bound check failure */
115 				DDPRINTF("ntfs_utf8_wput: need 2 bytes\n");
116                                 return 0;
117                         }
118 
119                         s[0] = 0xC0 | ((wc >> 6) & 0x1F);
120                         s[1] = 0x80 | ((wc) & 0x3F);
121                         return 2;
122                 } else {
123                         if (n < 1) {
124                                 /* bound check failure */
125 				DDPRINTF("ntfs_utf8_wput: need 1 byte\n");
126                                 return 0;
127                         }
128 
129                         s[0] = wc;
130                         return 1;
131                 }
132         }
133 }
134 
135 /*
136  * Compare two wide characters, returning 1, 0, -1 if the first is
137  * bigger, equal or lower than the second.
138  */
139 int
140 ntfs_utf8_wcmp(wchar wc1, wchar wc2)
141 {
142 	/* no conversions needed for utf8 */
143 
144 	if (wc1 == wc2)
145 		return 0;
146 	else
147 		return (int) wc1 - (int) wc2;
148 }
149