Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Matthew Garrett | 0635eb8 | 2013-04-15 13:09:45 -0700 | [diff] [blame] | 2 | #include <linux/ucs2_string.h> |
| 3 | #include <linux/module.h> |
| 4 | |
| 5 | /* Return the number of unicode characters in data */ |
| 6 | unsigned long |
| 7 | ucs2_strnlen(const ucs2_char_t *s, size_t maxlength) |
| 8 | { |
| 9 | unsigned long length = 0; |
| 10 | |
| 11 | while (*s++ != 0 && length < maxlength) |
| 12 | length++; |
| 13 | return length; |
| 14 | } |
| 15 | EXPORT_SYMBOL(ucs2_strnlen); |
| 16 | |
| 17 | unsigned long |
| 18 | ucs2_strlen(const ucs2_char_t *s) |
| 19 | { |
| 20 | return ucs2_strnlen(s, ~0UL); |
| 21 | } |
| 22 | EXPORT_SYMBOL(ucs2_strlen); |
| 23 | |
| 24 | /* |
| 25 | * Return the number of bytes is the length of this string |
| 26 | * Note: this is NOT the same as the number of unicode characters |
| 27 | */ |
| 28 | unsigned long |
| 29 | ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength) |
| 30 | { |
| 31 | return ucs2_strnlen(data, maxlength/sizeof(ucs2_char_t)) * sizeof(ucs2_char_t); |
| 32 | } |
| 33 | EXPORT_SYMBOL(ucs2_strsize); |
| 34 | |
Maximilian Luz | e4c89f9 | 2023-08-27 23:14:04 +0200 | [diff] [blame] | 35 | /** |
| 36 | * ucs2_strscpy() - Copy a UCS2 string into a sized buffer. |
| 37 | * |
| 38 | * @dst: Pointer to the destination buffer where to copy the string to. |
| 39 | * @src: Pointer to the source buffer where to copy the string from. |
| 40 | * @count: Size of the destination buffer, in UCS2 (16-bit) characters. |
| 41 | * |
| 42 | * Like strscpy(), only for UCS2 strings. |
| 43 | * |
| 44 | * Copy the source string @src, or as much of it as fits, into the destination |
| 45 | * buffer @dst. The behavior is undefined if the string buffers overlap. The |
| 46 | * destination buffer @dst is always NUL-terminated, unless it's zero-sized. |
| 47 | * |
| 48 | * Return: The number of characters copied into @dst (excluding the trailing |
| 49 | * %NUL terminator) or -E2BIG if @count is 0 or @src was truncated due to the |
| 50 | * destination buffer being too small. |
| 51 | */ |
| 52 | ssize_t ucs2_strscpy(ucs2_char_t *dst, const ucs2_char_t *src, size_t count) |
| 53 | { |
| 54 | long res; |
| 55 | |
| 56 | /* |
| 57 | * Ensure that we have a valid amount of space. We need to store at |
| 58 | * least one NUL-character. |
| 59 | */ |
| 60 | if (count == 0 || WARN_ON_ONCE(count > INT_MAX / sizeof(*dst))) |
| 61 | return -E2BIG; |
| 62 | |
| 63 | /* |
| 64 | * Copy at most 'count' characters, return early if we find a |
| 65 | * NUL-terminator. |
| 66 | */ |
| 67 | for (res = 0; res < count; res++) { |
| 68 | ucs2_char_t c; |
| 69 | |
| 70 | c = src[res]; |
| 71 | dst[res] = c; |
| 72 | |
| 73 | if (!c) |
| 74 | return res; |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * The loop above terminated without finding a NUL-terminator, |
| 79 | * exceeding the 'count': Enforce proper NUL-termination and return |
| 80 | * error. |
| 81 | */ |
| 82 | dst[count - 1] = 0; |
| 83 | return -E2BIG; |
| 84 | } |
| 85 | EXPORT_SYMBOL(ucs2_strscpy); |
| 86 | |
Matthew Garrett | 0635eb8 | 2013-04-15 13:09:45 -0700 | [diff] [blame] | 87 | int |
| 88 | ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len) |
| 89 | { |
| 90 | while (1) { |
| 91 | if (len == 0) |
| 92 | return 0; |
| 93 | if (*a < *b) |
| 94 | return -1; |
| 95 | if (*a > *b) |
| 96 | return 1; |
| 97 | if (*a == 0) /* implies *b == 0 */ |
| 98 | return 0; |
| 99 | a++; |
| 100 | b++; |
| 101 | len--; |
| 102 | } |
| 103 | } |
| 104 | EXPORT_SYMBOL(ucs2_strncmp); |
Peter Jones | 7350026 | 2016-02-08 14:48:11 -0500 | [diff] [blame] | 105 | |
| 106 | unsigned long |
| 107 | ucs2_utf8size(const ucs2_char_t *src) |
| 108 | { |
| 109 | unsigned long i; |
| 110 | unsigned long j = 0; |
| 111 | |
Lukas Wunner | cf289ce | 2016-08-03 10:16:02 +0200 | [diff] [blame] | 112 | for (i = 0; src[i]; i++) { |
Peter Jones | 7350026 | 2016-02-08 14:48:11 -0500 | [diff] [blame] | 113 | u16 c = src[i]; |
| 114 | |
Jason Andryuk | a680759 | 2016-02-12 23:13:33 +0000 | [diff] [blame] | 115 | if (c >= 0x800) |
Peter Jones | 7350026 | 2016-02-08 14:48:11 -0500 | [diff] [blame] | 116 | j += 3; |
Jason Andryuk | a680759 | 2016-02-12 23:13:33 +0000 | [diff] [blame] | 117 | else if (c >= 0x80) |
Peter Jones | 7350026 | 2016-02-08 14:48:11 -0500 | [diff] [blame] | 118 | j += 2; |
| 119 | else |
| 120 | j += 1; |
| 121 | } |
| 122 | |
| 123 | return j; |
| 124 | } |
| 125 | EXPORT_SYMBOL(ucs2_utf8size); |
| 126 | |
| 127 | /* |
| 128 | * copy at most maxlength bytes of whole utf8 characters to dest from the |
| 129 | * ucs2 string src. |
| 130 | * |
| 131 | * The return value is the number of characters copied, not including the |
| 132 | * final NUL character. |
| 133 | */ |
| 134 | unsigned long |
| 135 | ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength) |
| 136 | { |
| 137 | unsigned int i; |
| 138 | unsigned long j = 0; |
| 139 | unsigned long limit = ucs2_strnlen(src, maxlength); |
| 140 | |
| 141 | for (i = 0; maxlength && i < limit; i++) { |
| 142 | u16 c = src[i]; |
| 143 | |
Jason Andryuk | a680759 | 2016-02-12 23:13:33 +0000 | [diff] [blame] | 144 | if (c >= 0x800) { |
Peter Jones | 7350026 | 2016-02-08 14:48:11 -0500 | [diff] [blame] | 145 | if (maxlength < 3) |
| 146 | break; |
| 147 | maxlength -= 3; |
| 148 | dest[j++] = 0xe0 | (c & 0xf000) >> 12; |
Jason Andryuk | a680759 | 2016-02-12 23:13:33 +0000 | [diff] [blame] | 149 | dest[j++] = 0x80 | (c & 0x0fc0) >> 6; |
Peter Jones | 7350026 | 2016-02-08 14:48:11 -0500 | [diff] [blame] | 150 | dest[j++] = 0x80 | (c & 0x003f); |
Jason Andryuk | a680759 | 2016-02-12 23:13:33 +0000 | [diff] [blame] | 151 | } else if (c >= 0x80) { |
Peter Jones | 7350026 | 2016-02-08 14:48:11 -0500 | [diff] [blame] | 152 | if (maxlength < 2) |
| 153 | break; |
| 154 | maxlength -= 2; |
Jason Andryuk | a680759 | 2016-02-12 23:13:33 +0000 | [diff] [blame] | 155 | dest[j++] = 0xc0 | (c & 0x7c0) >> 6; |
| 156 | dest[j++] = 0x80 | (c & 0x03f); |
Peter Jones | 7350026 | 2016-02-08 14:48:11 -0500 | [diff] [blame] | 157 | } else { |
| 158 | maxlength -= 1; |
| 159 | dest[j++] = c & 0x7f; |
| 160 | } |
| 161 | } |
| 162 | if (maxlength) |
| 163 | dest[j] = '\0'; |
| 164 | return j; |
| 165 | } |
| 166 | EXPORT_SYMBOL(ucs2_as_utf8); |
Randy Dunlap | 09088a4 | 2018-06-07 17:10:55 -0700 | [diff] [blame] | 167 | |
| 168 | MODULE_LICENSE("GPL v2"); |