1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/module.h>
3#include <linux/kernel.h>
4#include <linux/string.h>
5#include <linux/slab.h>
6#include <linux/parser.h>
7#include <linux/errno.h>
8#include <linux/stringhash.h>
9
10#include "utf8n.h"
11
12int utf8_validate(const struct unicode_map *um, const struct qstr *str)
13{
14	if (utf8nlen(um, UTF8_NFDI, str->name, str->len) < 0)
15		return -1;
16	return 0;
17}
18EXPORT_SYMBOL(utf8_validate);
19
20int utf8_strncmp(const struct unicode_map *um,
21		 const struct qstr *s1, const struct qstr *s2)
22{
23	struct utf8cursor cur1, cur2;
24	int c1, c2;
25
26	if (utf8ncursor(&cur1, um, UTF8_NFDI, s1->name, s1->len) < 0)
27		return -EINVAL;
28
29	if (utf8ncursor(&cur2, um, UTF8_NFDI, s2->name, s2->len) < 0)
30		return -EINVAL;
31
32	do {
33		c1 = utf8byte(&cur1);
34		c2 = utf8byte(&cur2);
35
36		if (c1 < 0 || c2 < 0)
37			return -EINVAL;
38		if (c1 != c2)
39			return 1;
40	} while (c1);
41
42	return 0;
43}
44EXPORT_SYMBOL(utf8_strncmp);
45
46int utf8_strncasecmp(const struct unicode_map *um,
47		     const struct qstr *s1, const struct qstr *s2)
48{
49	struct utf8cursor cur1, cur2;
50	int c1, c2;
51
52	if (utf8ncursor(&cur1, um, UTF8_NFDICF, s1->name, s1->len) < 0)
53		return -EINVAL;
54
55	if (utf8ncursor(&cur2, um, UTF8_NFDICF, s2->name, s2->len) < 0)
56		return -EINVAL;
57
58	do {
59		c1 = utf8byte(&cur1);
60		c2 = utf8byte(&cur2);
61
62		if (c1 < 0 || c2 < 0)
63			return -EINVAL;
64		if (c1 != c2)
65			return 1;
66	} while (c1);
67
68	return 0;
69}
70EXPORT_SYMBOL(utf8_strncasecmp);
71
72/* String cf is expected to be a valid UTF-8 casefolded
73 * string.
74 */
75int utf8_strncasecmp_folded(const struct unicode_map *um,
76			    const struct qstr *cf,
77			    const struct qstr *s1)
78{
79	struct utf8cursor cur1;
80	int c1, c2;
81	int i = 0;
82
83	if (utf8ncursor(&cur1, um, UTF8_NFDICF, s1->name, s1->len) < 0)
84		return -EINVAL;
85
86	do {
87		c1 = utf8byte(&cur1);
88		c2 = cf->name[i++];
89		if (c1 < 0)
90			return -EINVAL;
91		if (c1 != c2)
92			return 1;
93	} while (c1);
94
95	return 0;
96}
97EXPORT_SYMBOL(utf8_strncasecmp_folded);
98
99int utf8_casefold(const struct unicode_map *um, const struct qstr *str,
100		  unsigned char *dest, size_t dlen)
101{
102	struct utf8cursor cur;
103	size_t nlen = 0;
104
105	if (utf8ncursor(&cur, um, UTF8_NFDICF, str->name, str->len) < 0)
106		return -EINVAL;
107
108	for (nlen = 0; nlen < dlen; nlen++) {
109		int c = utf8byte(&cur);
110
111		dest[nlen] = c;
112		if (!c)
113			return nlen;
114		if (c == -1)
115			break;
116	}
117	return -EINVAL;
118}
119EXPORT_SYMBOL(utf8_casefold);
120
121int utf8_casefold_hash(const struct unicode_map *um, const void *salt,
122		       struct qstr *str)
123{
124	struct utf8cursor cur;
125	int c;
126	unsigned long hash = init_name_hash(salt);
127
128	if (utf8ncursor(&cur, um, UTF8_NFDICF, str->name, str->len) < 0)
129		return -EINVAL;
130
131	while ((c = utf8byte(&cur))) {
132		if (c < 0)
133			return -EINVAL;
134		hash = partial_name_hash((unsigned char)c, hash);
135	}
136	str->hash = end_name_hash(hash);
137	return 0;
138}
139EXPORT_SYMBOL(utf8_casefold_hash);
140
141int utf8_normalize(const struct unicode_map *um, const struct qstr *str,
142		   unsigned char *dest, size_t dlen)
143{
144	struct utf8cursor cur;
145	ssize_t nlen = 0;
146
147	if (utf8ncursor(&cur, um, UTF8_NFDI, str->name, str->len) < 0)
148		return -EINVAL;
149
150	for (nlen = 0; nlen < dlen; nlen++) {
151		int c = utf8byte(&cur);
152
153		dest[nlen] = c;
154		if (!c)
155			return nlen;
156		if (c == -1)
157			break;
158	}
159	return -EINVAL;
160}
161EXPORT_SYMBOL(utf8_normalize);
162
163static const struct utf8data *find_table_version(const struct utf8data *table,
164		size_t nr_entries, unsigned int version)
165{
166	size_t i = nr_entries - 1;
167
168	while (version < table[i].maxage)
169		i--;
170	if (version > table[i].maxage)
171		return NULL;
172	return &table[i];
173}
174
175struct unicode_map *utf8_load(unsigned int version)
176{
177	struct unicode_map *um;
178
179	um = kzalloc(sizeof(struct unicode_map), GFP_KERNEL);
180	if (!um)
181		return ERR_PTR(-ENOMEM);
182	um->version = version;
183
184	um->tables = symbol_request(utf8_data_table);
185	if (!um->tables)
186		goto out_free_um;
187
188	if (!utf8version_is_supported(um, version))
189		goto out_symbol_put;
190	um->ntab[UTF8_NFDI] = find_table_version(um->tables->utf8nfdidata,
191			um->tables->utf8nfdidata_size, um->version);
192	if (!um->ntab[UTF8_NFDI])
193		goto out_symbol_put;
194	um->ntab[UTF8_NFDICF] = find_table_version(um->tables->utf8nfdicfdata,
195			um->tables->utf8nfdicfdata_size, um->version);
196	if (!um->ntab[UTF8_NFDICF])
197		goto out_symbol_put;
198	return um;
199
200out_symbol_put:
201	symbol_put(um->tables);
202out_free_um:
203	kfree(um);
204	return ERR_PTR(-EINVAL);
205}
206EXPORT_SYMBOL(utf8_load);
207
208void utf8_unload(struct unicode_map *um)
209{
210	if (um) {
211		symbol_put(utf8_data_table);
212		kfree(um);
213	}
214}
215EXPORT_SYMBOL(utf8_unload);
216
217