1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * 3 *
4 * Copyright (C) 2019-2021 Paragon Software Gm 4 * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
5 * 5 *
6 */ 6 */
7 7
8 #include <linux/kernel.h> 8 #include <linux/kernel.h>
9 #include <linux/types.h> 9 #include <linux/types.h>
10 10
11 #include "ntfs_fs.h" 11 #include "ntfs_fs.h"
12 12
13 static inline u16 upcase_unicode_char(const u1 13 static inline u16 upcase_unicode_char(const u16 *upcase, u16 chr)
14 { 14 {
15 if (chr < 'a') 15 if (chr < 'a')
16 return chr; 16 return chr;
17 17
18 if (chr <= 'z') 18 if (chr <= 'z')
19 return chr - ('a' - 'A'); 19 return chr - ('a' - 'A');
20 20
21 return upcase[chr]; 21 return upcase[chr];
22 } 22 }
23 23
24 /* 24 /*
25 * ntfs_cmp_names 25 * ntfs_cmp_names
26 * 26 *
27 * Thanks Kari Argillander <kari.argillander@g 27 * Thanks Kari Argillander <kari.argillander@gmail.com> for idea and implementation 'bothcase'
28 * 28 *
29 * Straight way to compare names: 29 * Straight way to compare names:
30 * - Case insensitive 30 * - Case insensitive
31 * - If name equals and 'bothcases' then 31 * - If name equals and 'bothcases' then
32 * - Case sensitive 32 * - Case sensitive
33 * 'Straight way' code scans input names twice 33 * 'Straight way' code scans input names twice in worst case.
34 * Optimized code scans input names only once. 34 * Optimized code scans input names only once.
35 */ 35 */
36 int ntfs_cmp_names(const __le16 *s1, size_t l1 36 int ntfs_cmp_names(const __le16 *s1, size_t l1, const __le16 *s2, size_t l2,
37 const u16 *upcase, bool bot 37 const u16 *upcase, bool bothcase)
38 { 38 {
39 int diff1 = 0; 39 int diff1 = 0;
40 int diff2; 40 int diff2;
41 size_t len = min(l1, l2); 41 size_t len = min(l1, l2);
42 42
43 if (!bothcase && upcase) 43 if (!bothcase && upcase)
44 goto case_insentive; 44 goto case_insentive;
45 45
46 for (; len; s1++, s2++, len--) { 46 for (; len; s1++, s2++, len--) {
47 diff1 = le16_to_cpu(*s1) - le1 47 diff1 = le16_to_cpu(*s1) - le16_to_cpu(*s2);
48 if (diff1) { 48 if (diff1) {
49 if (bothcase && upcase 49 if (bothcase && upcase)
50 goto case_inse 50 goto case_insentive;
51 51
52 return diff1; 52 return diff1;
53 } 53 }
54 } 54 }
55 return l1 - l2; 55 return l1 - l2;
56 56
57 case_insentive: 57 case_insentive:
58 for (; len; s1++, s2++, len--) { 58 for (; len; s1++, s2++, len--) {
59 diff2 = upcase_unicode_char(up 59 diff2 = upcase_unicode_char(upcase, le16_to_cpu(*s1)) -
60 upcase_unicode_char(up 60 upcase_unicode_char(upcase, le16_to_cpu(*s2));
61 if (diff2) 61 if (diff2)
62 return diff2; 62 return diff2;
63 } 63 }
64 64
65 diff2 = l1 - l2; 65 diff2 = l1 - l2;
66 return diff2 ? diff2 : diff1; 66 return diff2 ? diff2 : diff1;
67 } 67 }
68 68
69 int ntfs_cmp_names_cpu(const struct cpu_str *u 69 int ntfs_cmp_names_cpu(const struct cpu_str *uni1, const struct le_str *uni2,
70 const u16 *upcase, bool 70 const u16 *upcase, bool bothcase)
71 { 71 {
72 const u16 *s1 = uni1->name; 72 const u16 *s1 = uni1->name;
73 const __le16 *s2 = uni2->name; 73 const __le16 *s2 = uni2->name;
74 size_t l1 = uni1->len; 74 size_t l1 = uni1->len;
75 size_t l2 = uni2->len; 75 size_t l2 = uni2->len;
76 size_t len = min(l1, l2); 76 size_t len = min(l1, l2);
77 int diff1 = 0; 77 int diff1 = 0;
78 int diff2; 78 int diff2;
79 79
80 if (!bothcase && upcase) 80 if (!bothcase && upcase)
81 goto case_insentive; 81 goto case_insentive;
82 82
83 for (; len; s1++, s2++, len--) { 83 for (; len; s1++, s2++, len--) {
84 diff1 = *s1 - le16_to_cpu(*s2) 84 diff1 = *s1 - le16_to_cpu(*s2);
85 if (diff1) { 85 if (diff1) {
86 if (bothcase && upcase 86 if (bothcase && upcase)
87 goto case_inse 87 goto case_insentive;
88 88
89 return diff1; 89 return diff1;
90 } 90 }
91 } 91 }
92 return l1 - l2; 92 return l1 - l2;
93 93
94 case_insentive: 94 case_insentive:
95 for (; len; s1++, s2++, len--) { 95 for (; len; s1++, s2++, len--) {
96 diff2 = upcase_unicode_char(up 96 diff2 = upcase_unicode_char(upcase, *s1) -
97 upcase_unicode_char(up 97 upcase_unicode_char(upcase, le16_to_cpu(*s2));
98 if (diff2) 98 if (diff2)
99 return diff2; 99 return diff2;
100 } 100 }
101 101
102 diff2 = l1 - l2; 102 diff2 = l1 - l2;
103 return diff2 ? diff2 : diff1; 103 return diff2 ? diff2 : diff1;
104 } 104 }
105 <<
106 /* Helper function for ntfs_d_hash. */ <<
107 unsigned long ntfs_names_hash(const u16 *name, <<
108 unsigned long ha <<
109 { <<
110 while (len--) { <<
111 unsigned int c = upcase_unicod <<
112 hash = partial_name_hash(c, ha <<
113 } <<
114 <<
115 return hash; <<
116 } <<
117 105
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