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 */
109