projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| a1d312de | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 1da177e4 LT |
2 | /* |
| 3 | * collate.c - NTFS kernel collation handling. Part of the Linux-NTFS project. | |
| 4 | * | |
| 5 | * Copyright (c) 2004 Anton Altaparmakov | |
| 1da177e4 LT |
6 | */ |
| 7 | ||
| 8 | #include "collate.h" | |
| 9 | #include "debug.h" | |
| 10 | #include "ntfs.h" | |
| 11 | ||
| 12 | static int ntfs_collate_binary(ntfs_volume *vol, | |
| 13 | const void *data1, const int data1_len, | |
| 14 | const void *data2, const int data2_len) | |
| 15 | { | |
| 16 | int rc; | |
| 17 | ||
| 18 | ntfs_debug("Entering."); | |
| 19 | rc = memcmp(data1, data2, min(data1_len, data2_len)); | |
| 20 | if (!rc && (data1_len != data2_len)) { | |
| 21 | if (data1_len < data2_len) | |
| 22 | rc = -1; | |
| 23 | else | |
| 24 | rc = 1; | |
| 25 | } | |
| 26 | ntfs_debug("Done, returning %i", rc); | |
| 27 | return rc; | |
| 28 | } | |
| 29 | ||
| 30 | static int ntfs_collate_ntofs_ulong(ntfs_volume *vol, | |
| 31 | const void *data1, const int data1_len, | |
| 32 | const void *data2, const int data2_len) | |
| 33 | { | |
| 34 | int rc; | |
| 35 | u32 d1, d2; | |
| 36 | ||
| 37 | ntfs_debug("Entering."); | |
| 38 | // FIXME: We don't really want to bug here. | |
| 39 | BUG_ON(data1_len != data2_len); | |
| 40 | BUG_ON(data1_len != 4); | |
| 41 | d1 = le32_to_cpup(data1); | |
| 42 | d2 = le32_to_cpup(data2); | |
| 43 | if (d1 < d2) | |
| 44 | rc = -1; | |
| 45 | else { | |
| 46 | if (d1 == d2) | |
| 47 | rc = 0; | |
| 48 | else | |
| 49 | rc = 1; | |
| 50 | } | |
| 51 | ntfs_debug("Done, returning %i", rc); | |
| 52 | return rc; | |
| 53 | } | |
| 54 | ||
| 55 | typedef int (*ntfs_collate_func_t)(ntfs_volume *, const void *, const int, | |
| 56 | const void *, const int); | |
| 57 | ||
| 58 | static ntfs_collate_func_t ntfs_do_collate0x0[3] = { | |
| 59 | ntfs_collate_binary, | |
| 60 | NULL/*ntfs_collate_file_name*/, | |
| 61 | NULL/*ntfs_collate_unicode_string*/, | |
| 62 | }; | |
| 63 | ||
| 64 | static ntfs_collate_func_t ntfs_do_collate0x1[4] = { | |
| 65 | ntfs_collate_ntofs_ulong, | |
| 66 | NULL/*ntfs_collate_ntofs_sid*/, | |
| 67 | NULL/*ntfs_collate_ntofs_security_hash*/, | |
| 68 | NULL/*ntfs_collate_ntofs_ulongs*/, | |
| 69 | }; | |
| 70 | ||
| 71 | /** | |
| 72 | * ntfs_collate - collate two data items using a specified collation rule | |
| 73 | * @vol: ntfs volume to which the data items belong | |
| 74 | * @cr: collation rule to use when comparing the items | |
| 75 | * @data1: first data item to collate | |
| 76 | * @data1_len: length in bytes of @data1 | |
| 77 | * @data2: second data item to collate | |
| 78 | * @data2_len: length in bytes of @data2 | |
| 79 | * | |
| 80 | * Collate the two data items @data1 and @data2 using the collation rule @cr | |
| 81 | * and return -1, 0, ir 1 if @data1 is found, respectively, to collate before, | |
| 82 | * to match, or to collate after @data2. | |
| 83 | * | |
| 84 | * For speed we use the collation rule @cr as an index into two tables of | |
| 85 | * function pointers to call the appropriate collation function. | |
| 86 | */ | |
| 87 | int ntfs_collate(ntfs_volume *vol, COLLATION_RULE cr, | |
| 88 | const void *data1, const int data1_len, | |
| 89 | const void *data2, const int data2_len) { | |
| 90 | int i; | |
| 91 | ||
| 92 | ntfs_debug("Entering."); | |
| 93 | /* | |
| 94 | * FIXME: At the moment we only support COLLATION_BINARY and | |
| 95 | * COLLATION_NTOFS_ULONG, so we BUG() for everything else for now. | |
| 96 | */ | |
| 97 | BUG_ON(cr != COLLATION_BINARY && cr != COLLATION_NTOFS_ULONG); | |
| 98 | i = le32_to_cpu(cr); | |
| 99 | BUG_ON(i < 0); | |
| 100 | if (i <= 0x02) | |
| 101 | return ntfs_do_collate0x0[i](vol, data1, data1_len, | |
| 102 | data2, data2_len); | |
| 103 | BUG_ON(i < 0x10); | |
| 104 | i -= 0x10; | |
| 105 | if (likely(i <= 3)) | |
| 106 | return ntfs_do_collate0x1[i](vol, data1, data1_len, | |
| 107 | data2, data2_len); | |
| 108 | BUG(); | |
| 109 | return 0; | |
| 110 | } |