1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * collate.c - NTFS kernel collation handling. Part of the Linux-NTFS project. 4 * 5 * Copyright (c) 2004 Anton Altaparmakov 6 */ 7 8#include "collate.h" 9#include "debug.h" 10#include "ntfs.h" 11 12static 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 30static 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 55typedef int (*ntfs_collate_func_t)(ntfs_volume *, const void *, const int, 56 const void *, const int); 57 58static 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 64static 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 */ 87int 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} 111