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9
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <linux/nls.h>
14#include <linux/errno.h>
15
16static const wchar_t charset2uni[256] = {
17
18 0x0000, 0x0001, 0x0002, 0x0003,
19 0x0004, 0x0005, 0x0006, 0x0007,
20 0x0008, 0x0009, 0x000a, 0x000b,
21 0x000c, 0x000d, 0x000e, 0x000f,
22
23 0x0010, 0x0011, 0x0012, 0x0013,
24 0x0014, 0x0015, 0x0016, 0x0017,
25 0x0018, 0x0019, 0x001a, 0x001b,
26 0x001c, 0x001d, 0x001e, 0x001f,
27
28 0x0020, 0x0021, 0x0022, 0x0023,
29 0x0024, 0x0025, 0x0026, 0x0027,
30 0x0028, 0x0029, 0x002a, 0x002b,
31 0x002c, 0x002d, 0x002e, 0x002f,
32
33 0x0030, 0x0031, 0x0032, 0x0033,
34 0x0034, 0x0035, 0x0036, 0x0037,
35 0x0038, 0x0039, 0x003a, 0x003b,
36 0x003c, 0x003d, 0x003e, 0x003f,
37
38 0x0040, 0x0041, 0x0042, 0x0043,
39 0x0044, 0x0045, 0x0046, 0x0047,
40 0x0048, 0x0049, 0x004a, 0x004b,
41 0x004c, 0x004d, 0x004e, 0x004f,
42
43 0x0050, 0x0051, 0x0052, 0x0053,
44 0x0054, 0x0055, 0x0056, 0x0057,
45 0x0058, 0x0059, 0x005a, 0x005b,
46 0x005c, 0x005d, 0x005e, 0x005f,
47
48 0x0060, 0x0061, 0x0062, 0x0063,
49 0x0064, 0x0065, 0x0066, 0x0067,
50 0x0068, 0x0069, 0x006a, 0x006b,
51 0x006c, 0x006d, 0x006e, 0x006f,
52
53 0x0070, 0x0071, 0x0072, 0x0073,
54 0x0074, 0x0075, 0x0076, 0x0077,
55 0x0078, 0x0079, 0x007a, 0x007b,
56 0x007c, 0x007d, 0x007e, 0x007f,
57};
58
59static const unsigned char page00[256] = {
60 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
61 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
62 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
63 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
64 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
65 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
66 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
67 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
68 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
69 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
70 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
71 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
72 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
73 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
74 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
75 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
76};
77
78static const unsigned char *const page_uni2charset[256] = {
79 page00,
80};
81
82static const unsigned char charset2lower[256] = {
83 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
84 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
85 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
86 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
87 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
88 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
89 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
90 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
91 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
92 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
93 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
94 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
95 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
96 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
97 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
98 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
99};
100
101static const unsigned char charset2upper[256] = {
102 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
103 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
104 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
105 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
106 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
107 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
108 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
109 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
110 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
111 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
112 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
113 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
114 0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
115 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
116 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
117 0x58, 0x59, 0x5a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
118};
119
120static int uni2char(wchar_t uni, unsigned char *out, int boundlen)
121{
122 const unsigned char *uni2charset;
123 unsigned char cl = uni & 0x00ff;
124 unsigned char ch = (uni & 0xff00) >> 8;
125
126 if (boundlen <= 0)
127 return -ENAMETOOLONG;
128
129 uni2charset = page_uni2charset[ch];
130 if (uni2charset && uni2charset[cl])
131 out[0] = uni2charset[cl];
132 else
133 return -EINVAL;
134 return 1;
135}
136
137static int char2uni(const unsigned char *rawstring, int boundlen, wchar_t *uni)
138{
139 *uni = charset2uni[*rawstring];
140 if (*uni == 0x0000)
141 return -EINVAL;
142 return 1;
143}
144
145static struct nls_table table = {
146 .charset = "ascii",
147 .uni2char = uni2char,
148 .char2uni = char2uni,
149 .charset2lower = charset2lower,
150 .charset2upper = charset2upper,
151};
152
153static int __init init_nls_ascii(void)
154{
155 return register_nls(&table);
156}
157
158static void __exit exit_nls_ascii(void)
159{
160 unregister_nls(&table);
161}
162
163module_init(init_nls_ascii)
164module_exit(exit_nls_ascii)
165
166MODULE_LICENSE("Dual BSD/GPL");
167