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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 | // 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; } |