| 1 | |
| 2 | #include <linux/ucs2_string.h>
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| 3 | #include <linux/module.h>
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| 4 |
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| 5 |
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| 6 | unsigned long
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| 7 | ucs2_strnlen(const ucs2_char_t *s, size_t maxlength)
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| 8 | {
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| 9 | unsigned long length = 0;
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| 10 |
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| 11 | while (length < maxlength && *s++ != 0)
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| 12 | length++;
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| 13 | return length;
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| 14 | }
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| 15 | EXPORT_SYMBOL(ucs2_strnlen);
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| 16 |
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| 17 | unsigned long
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| 18 | ucs2_strlen(const ucs2_char_t *s)
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| 19 | {
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| 20 | return ucs2_strnlen(s, ~0UL);
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| 21 | }
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| 22 | EXPORT_SYMBOL(ucs2_strlen);
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| 23 |
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| 24 | |
| 25 | * Return the number of bytes is the length of this string
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| 26 | * Note: this is NOT the same as the number of unicode characters
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| 27 |
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| 28 | unsigned long
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| 29 | ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength)
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| 30 | {
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| 31 | return ucs2_strnlen(data, maxlength/sizeof(ucs2_char_t)) * sizeof(ucs2_char_t);
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| 32 | }
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| 33 | EXPORT_SYMBOL(ucs2_strsize);
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| 34 |
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| 35 | |
| 36 | * ucs2_strscpy() - Copy a UCS2 string into a sized buffer.
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| 37 | *
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| 38 | * @dst: Pointer to the destination buffer where to copy the string to.
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| 39 | * @src: Pointer to the source buffer where to copy the string from.
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| 40 | * @count: Size of the destination buffer, in UCS2 (16-bit) characters.
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| 41 | *
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| 42 | * Like strscpy(), only for UCS2 strings.
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| 43 | *
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| 44 | * Copy the source string @src, or as much of it as fits, into the destination
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| 45 | * buffer @dst. The behavior is undefined if the string buffers overlap. The
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| 46 | * destination buffer @dst is always NUL-terminated, unless it's zero-sized.
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| 47 | *
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| 48 | * Return: The number of characters copied into @dst (excluding the trailing
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| 49 | * %NUL terminator) or -E2BIG if @count is 0 or @src was truncated due to the
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| 50 | * destination buffer being too small.
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| 51 |
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| 52 | ssize_t ucs2_strscpy(ucs2_char_t *dst, const ucs2_char_t *src, size_t count)
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| 53 | {
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| 54 | long res;
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| 55 |
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| 56 | |
| 57 | * Ensure that we have a valid amount of space. We need to store at
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| 58 | * least one NUL-character.
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| 59 |
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| 60 | if (count == 0 || WARN_ON_ONCE(count > INT_MAX / sizeof(*dst)))
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| 61 | return -E2BIG;
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| 62 |
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| 63 | |
| 64 | * Copy at most 'count' characters, return early if we find a
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| 65 | * NUL-terminator.
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| 66 |
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| 67 | for (res = 0; res < count; res++) {
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| 68 | ucs2_char_t c;
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| 69 |
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| 70 | c = src[res];
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| 71 | dst[res] = c;
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| 72 |
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| 73 | if (!c)
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| 74 | return res;
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| 75 | }
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| 76 |
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| 77 | |
| 78 | * The loop above terminated without finding a NUL-terminator,
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| 79 | * exceeding the 'count': Enforce proper NUL-termination and return
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| 80 | * error.
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| 81 |
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| 82 | dst[count - 1] = 0;
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| 83 | return -E2BIG;
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| 84 | }
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| 85 | EXPORT_SYMBOL(ucs2_strscpy);
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| 86 |
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| 87 | int
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| 88 | ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len)
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| 89 | {
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| 90 | while (1) {
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| 91 | if (len == 0)
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| 92 | return 0;
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| 93 | if (*a < *b)
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| 94 | return -1;
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| 95 | if (*a > *b)
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| 96 | return 1;
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| 97 | if (*a == 0)
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| 98 | return 0;
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| 99 | a++;
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| 100 | b++;
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| 101 | len--;
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| 102 | }
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| 103 | }
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| 104 | EXPORT_SYMBOL(ucs2_strncmp);
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| 105 |
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| 106 | unsigned long
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| 107 | ucs2_utf8size(const ucs2_char_t *src)
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| 108 | {
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| 109 | unsigned long i;
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| 110 | unsigned long j = 0;
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| 111 |
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| 112 | for (i = 0; src[i]; i++) {
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| 113 | u16 c = src[i];
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| 114 |
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| 115 | if (c >= 0x800)
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| 116 | j += 3;
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| 117 | else if (c >= 0x80)
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| 118 | j += 2;
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| 119 | else
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| 120 | j += 1;
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| 121 | }
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| 122 |
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| 123 | return j;
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| 124 | }
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| 125 | EXPORT_SYMBOL(ucs2_utf8size);
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| 126 |
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| 127 | |
| 128 | * copy at most maxlength bytes of whole utf8 characters to dest from the
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| 129 | * ucs2 string src.
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| 130 | *
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| 131 | * The return value is the number of characters copied, not including the
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| 132 | * final NUL character.
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| 133 |
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| 134 | unsigned long
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| 135 | ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength)
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| 136 | {
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| 137 | unsigned int i;
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| 138 | unsigned long j = 0;
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| 139 | unsigned long limit = ucs2_strnlen(src, maxlength);
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| 140 |
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| 141 | for (i = 0; maxlength && i < limit; i++) {
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| 142 | u16 c = src[i];
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| 143 |
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| 144 | if (c >= 0x800) {
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| 145 | if (maxlength < 3)
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| 146 | break;
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| 147 | maxlength -= 3;
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| 148 | dest[j++] = 0xe0 | (c & 0xf000) >> 12;
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| 149 | dest[j++] = 0x80 | (c & 0x0fc0) >> 6;
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| 150 | dest[j++] = 0x80 | (c & 0x003f);
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| 151 | } else if (c >= 0x80) {
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| 152 | if (maxlength < 2)
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| 153 | break;
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| 154 | maxlength -= 2;
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| 155 | dest[j++] = 0xc0 | (c & 0x7c0) >> 6;
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| 156 | dest[j++] = 0x80 | (c & 0x03f);
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| 157 | } else {
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| 158 | maxlength -= 1;
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| 159 | dest[j++] = c & 0x7f;
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| 160 | }
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| 161 | }
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| 162 | if (maxlength)
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| 163 | dest[j] = '\0';
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| 164 | return j;
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| 165 | }
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| 166 | EXPORT_SYMBOL(ucs2_as_utf8);
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| 167 |
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| 168 | MODULE_DESCRIPTION("UCS2 string handling");
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| 169 | MODULE_LICENSE("GPL v2");
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