1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (c) 2014 SGI.
4 * All rights reserved.
5 */
6
7 #ifndef UTF8NORM_H
8 #define UTF8NORM_H
9
10 #include <linux/types.h>
11 #include <linux/export.h>
12 #include <linux/string.h>
13 #include <linux/module.h>
14
15 /* Encoding a unicode version number as a single unsigned int. */
16 #define UNICODE_MAJ_SHIFT (16)
17 #define UNICODE_MIN_SHIFT (8)
18
19 #define UNICODE_AGE(MAJ, MIN, REV) \
20 (((unsigned int)(MAJ) << UNICODE_MAJ_SHIFT) | \
21 ((unsigned int)(MIN) << UNICODE_MIN_SHIFT) | \
22 ((unsigned int)(REV)))
23
24 /* Highest unicode version supported by the data tables. */
25 extern int utf8version_is_supported(u8 maj, u8 min, u8 rev);
26 extern int utf8version_latest(void);
27
28 /*
29 * Look for the correct const struct utf8data for a unicode version.
30 * Returns NULL if the version requested is too new.
31 *
32 * Two normalization forms are supported: nfdi and nfdicf.
33 *
34 * nfdi:
35 * - Apply unicode normalization form NFD.
36 * - Remove any Default_Ignorable_Code_Point.
37 *
38 * nfdicf:
39 * - Apply unicode normalization form NFD.
40 * - Remove any Default_Ignorable_Code_Point.
41 * - Apply a full casefold (C + F).
42 */
43 extern const struct utf8data *utf8nfdi(unsigned int maxage);
44 extern const struct utf8data *utf8nfdicf(unsigned int maxage);
45
46 /*
47 * Determine the maximum age of any unicode character in the string.
48 * Returns 0 if only unassigned code points are present.
49 * Returns -1 if the input is not valid UTF-8.
50 */
51 extern int utf8agemax(const struct utf8data *data, const char *s);
52 extern int utf8nagemax(const struct utf8data *data, const char *s, size_t len);
53
54 /*
55 * Determine the minimum age of any unicode character in the string.
56 * Returns 0 if any unassigned code points are present.
57 * Returns -1 if the input is not valid UTF-8.
58 */
59 extern int utf8agemin(const struct utf8data *data, const char *s);
60 extern int utf8nagemin(const struct utf8data *data, const char *s, size_t len);
61
62 /*
63 * Determine the length of the normalized from of the string,
64 * excluding any terminating NULL byte.
65 * Returns 0 if only ignorable code points are present.
66 * Returns -1 if the input is not valid UTF-8.
67 */
68 extern ssize_t utf8len(const struct utf8data *data, const char *s);
69 extern ssize_t utf8nlen(const struct utf8data *data, const char *s, size_t len);
70
71 /* Needed in struct utf8cursor below. */
72 #define UTF8HANGULLEAF (12)
73
74 /*
75 * Cursor structure used by the normalizer.
76 */
77 struct utf8cursor {
78 const struct utf8data *data;
79 const char *s;
80 const char *p;
81 const char *ss;
82 const char *sp;
83 unsigned int len;
84 unsigned int slen;
85 short int ccc;
86 short int nccc;
87 unsigned char hangul[UTF8HANGULLEAF];
88 };
89
90 /*
91 * Initialize a utf8cursor to normalize a string.
92 * Returns 0 on success.
93 * Returns -1 on failure.
94 */
95 extern int utf8cursor(struct utf8cursor *u8c, const struct utf8data *data,
96 const char *s);
97 extern int utf8ncursor(struct utf8cursor *u8c, const struct utf8data *data,
98 const char *s, size_t len);
99
100 /*
101 * Get the next byte in the normalization.
102 * Returns a value > 0 && < 256 on success.
103 * Returns 0 when the end of the normalization is reached.
104 * Returns -1 if the string being normalized is not valid UTF-8.
105 */
106 extern int utf8byte(struct utf8cursor *u8c);
107
108 #endif /* UTF8NORM_H */