// SPDX-License-Identifier: GPL-2.0 #include <linux/ucs2_string.h> #include <linux/module.h> /* Return the number of unicode characters in data */ unsigned long ucs2_strnlen(const ucs2_char_t *s, size_t maxlength) { unsigned long length = 0; while (*s++ != 0 && length < maxlength) length++; return length; } EXPORT_SYMBOL(ucs2_strnlen); unsigned long ucs2_strlen(const ucs2_char_t *s) { return ucs2_strnlen(s, ~0UL); } EXPORT_SYMBOL(ucs2_strlen); /* * Return the number of bytes is the length of this string * Note: this is NOT the same as the number of unicode characters */ unsigned long ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength) { return ucs2_strnlen(data, maxlength/sizeof(ucs2_char_t)) * sizeof(ucs2_char_t); } EXPORT_SYMBOL(ucs2_strsize); int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len) { while (1) { if (len == 0) return 0; if (*a < *b) return -1; if (*a > *b) return 1; if (*a == 0) /* implies *b == 0 */ return 0; a++; b++; len--; } } EXPORT_SYMBOL(ucs2_strncmp); unsigned long ucs2_utf8size(const ucs2_char_t *src) { unsigned long i; unsigned long j = 0; for (i = 0; src[i]; i++) { u16 c = src[i]; if (c >= 0x800) j += 3; else if (c >= 0x80) j += 2; else j += 1; } return j; } EXPORT_SYMBOL(ucs2_utf8size); /* * copy at most maxlength bytes of whole utf8 characters to dest from the * ucs2 string src. * * The return value is the number of characters copied, not including the * final NUL character. */ unsigned long ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength) { unsigned int i; unsigned long j = 0; unsigned long limit = ucs2_strnlen(src, maxlength); for (i = 0; maxlength && i < limit; i++) { u16 c = src[i]; if (c >= 0x800) { if (maxlength < 3) break; maxlength -= 3; dest[j++] = 0xe0 | (c & 0xf000) >> 12; dest[j++] = 0x80 | (c & 0x0fc0) >> 6; dest[j++] = 0x80 | (c & 0x003f); } else if (c >= 0x80) { if (maxlength < 2) break; maxlength -= 2; dest[j++] = 0xc0 | (c & 0x7c0) >> 6; dest[j++] = 0x80 | (c & 0x03f); } else { maxlength -= 1; dest[j++] = c & 0x7f; } } if (maxlength) dest[j] = '\0'; return j; } EXPORT_SYMBOL(ucs2_as_utf8); MODULE_LICENSE("GPL v2");