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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293// SPDX-License-Identifier: GPL-2.0-or-later/* * WMI string utility functions. * * Copyright (C) 2025 Armin Wolf <W_Armin@gmx.de> */
#include <linux/build_bug.h>#include <linux/compiler_types.h>#include <linux/err.h>#include <linux/export.h>#include <linux/nls.h>#include <linux/limits.h>#include <linux/types.h>#include <linux/wmi.h>
#include <asm/byteorder.h>
static_assert(sizeof(__le16) == sizeof(wchar_t));
/** * wmi_string_to_utf8s - Convert a WMI string into a UTF8 string. * @str: WMI string representation * @dst: Buffer to fill with UTF8 characters * @length: Length of the destination buffer * * Convert as WMI string into a standard UTF8 string. The conversion will stop * once a NUL character is detected or when the buffer is full. Any invalid UTF16 * characters will be ignored. The resulting UTF8 string will always be NUL-terminated * when this function returns successfully. * * Return: Length of the resulting UTF8 string or negative errno code on failure. */ssize_t wmi_string_to_utf8s(const struct wmi_string *str, u8 *dst, size_t length){ /* Contains the maximum number of UTF16 code points to read */ int inlen = le16_to_cpu(str->length) / 2; int ret;
if (length < 1) return -EINVAL;
/* We must leave room for the NUL character at the end of the destination buffer */ ret = utf16s_to_utf8s((__force const wchar_t *)str->chars, inlen, UTF16_LITTLE_ENDIAN, dst, length - 1); if (ret < 0) return ret;
dst[ret] = '\0';
return ret;}EXPORT_SYMBOL_GPL(wmi_string_to_utf8s);
/** * wmi_string_from_utf8s - Convert a UTF8 string into a WMI string. * @str: WMI string representation * @max_chars: Maximum number of UTF16 code points to store inside the WMI string * @src: UTF8 string to convert * @src_length: Length of the source string without any trailing NUL-characters * * Convert a UTF8 string into a WMI string. The conversion will stop when the WMI string is * full. The resulting WMI string will always be NUL-terminated and have its length field set * to and appropriate value when this function returns successfully. * * Return: Number of UTF16 code points inside the WMI string or negative errno code on failure. */ssize_t wmi_string_from_utf8s(struct wmi_string *str, size_t max_chars, const u8 *src, size_t src_length){ size_t str_length; int ret;
if (max_chars < 1) return -EINVAL;
/* We must leave room for the NUL character at the end of the WMI string */ ret = utf8s_to_utf16s(src, src_length, UTF16_LITTLE_ENDIAN, (__force wchar_t *)str->chars, max_chars - 1); if (ret < 0) return ret;
str_length = (ret + 1) * sizeof(u16); if (str_length > U16_MAX) return -EOVERFLOW;
str->length = cpu_to_le16(str_length); str->chars[ret] = '\0';
return ret;}EXPORT_SYMBOL_GPL(wmi_string_from_utf8s);