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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /fs/ntfs3/upcase.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | fs/ntfs3/upcase.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/fs/ntfs3/upcase.c b/fs/ntfs3/upcase.c new file mode 100644 index 000000000..b5e8256fd --- /dev/null +++ b/fs/ntfs3/upcase.c @@ -0,0 +1,104 @@ +// 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; +} |