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// SPDX-License-Identifier: GPL-2.0
/*
*
* Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
*
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include "ntfs_fs.h"
static inline u16 upcase_unicode_char(const u16 *upcase, u16 chr)
{
if (chr < 'a')
return chr;
if (chr <= 'z')
return chr - ('a' - 'A');
return upcase[chr];
}
/*
* ntfs_cmp_names
*
* Thanks Kari Argillander <kari.argillander@gmail.com> for idea and implementation 'bothcase'
*
* Straight way to compare names:
* - Case insensitive
* - If name equals and 'bothcases' then
* - Case sensitive
* 'Straight way' code scans input names twice in worst case.
* Optimized code scans input names only once.
*/
int ntfs_cmp_names(const __le16 *s1, size_t l1, const __le16 *s2, size_t l2,
const u16 *upcase, bool bothcase)
{
int diff1 = 0;
int diff2;
size_t len = min(l1, l2);
if (!bothcase && upcase)
goto case_insentive;
for (; len; s1++, s2++, len--) {
diff1 = le16_to_cpu(*s1) - le16_to_cpu(*s2);
if (diff1) {
if (bothcase && upcase)
goto case_insentive;
return diff1;
}
}
return l1 - l2;
case_insentive:
for (; len; s1++, s2++, len--) {
diff2 = upcase_unicode_char(upcase, le16_to_cpu(*s1)) -
upcase_unicode_char(upcase, le16_to_cpu(*s2));
if (diff2)
return diff2;
}
diff2 = l1 - l2;
return diff2 ? diff2 : diff1;
}
int ntfs_cmp_names_cpu(const struct cpu_str *uni1, const struct le_str *uni2,
const u16 *upcase, bool bothcase)
{
const u16 *s1 = uni1->name;
const __le16 *s2 = uni2->name;
size_t l1 = uni1->len;
size_t l2 = uni2->len;
size_t len = min(l1, l2);
int diff1 = 0;
int diff2;
if (!bothcase && upcase)
goto case_insentive;
for (; len; s1++, s2++, len--) {
diff1 = *s1 - le16_to_cpu(*s2);
if (diff1) {
if (bothcase && upcase)
goto case_insentive;
return diff1;
}
}
return l1 - l2;
case_insentive:
for (; len; s1++, s2++, len--) {
diff2 = upcase_unicode_char(upcase, *s1) -
upcase_unicode_char(upcase, le16_to_cpu(*s2));
if (diff2)
return diff2;
}
diff2 = l1 - l2;
return diff2 ? diff2 : diff1;
}
/* Helper function for ntfs_d_hash. */
unsigned long ntfs_names_hash(const u16 *name, size_t len, const u16 *upcase,
unsigned long hash)
{
while (len--) {
unsigned int c = upcase_unicode_char(upcase, *name++);
hash = partial_name_hash(c, hash);
}
return hash;
}
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