1 /* 2 * collate.c - NTFS kernel collation handling. Part of the Linux-NTFS project. 3 * 4 * Copyright (c) 2004 Anton Altaparmakov 5 * 6 * This program/include file is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as published 8 * by the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program/include file is distributed in the hope that it will be 12 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty 13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program (in the main directory of the Linux-NTFS 18 * distribution in the file COPYING); if not, write to the Free Software 19 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #include "collate.h" 23 #include "debug.h" 24 #include "ntfs.h" 25 26 static int ntfs_collate_binary(ntfs_volume *vol, 27 const void *data1, const int data1_len, 28 const void *data2, const int data2_len) 29 { 30 int rc; 31 32 ntfs_debug("Entering."); 33 rc = memcmp(data1, data2, min(data1_len, data2_len)); 34 if (!rc && (data1_len != data2_len)) { 35 if (data1_len < data2_len) 36 rc = -1; 37 else 38 rc = 1; 39 } 40 ntfs_debug("Done, returning %i", rc); 41 return rc; 42 } 43 44 static int ntfs_collate_ntofs_ulong(ntfs_volume *vol, 45 const void *data1, const int data1_len, 46 const void *data2, const int data2_len) 47 { 48 int rc; 49 u32 d1, d2; 50 51 ntfs_debug("Entering."); 52 // FIXME: We don't really want to bug here. 53 BUG_ON(data1_len != data2_len); 54 BUG_ON(data1_len != 4); 55 d1 = le32_to_cpup(data1); 56 d2 = le32_to_cpup(data2); 57 if (d1 < d2) 58 rc = -1; 59 else { 60 if (d1 == d2) 61 rc = 0; 62 else 63 rc = 1; 64 } 65 ntfs_debug("Done, returning %i", rc); 66 return rc; 67 } 68 69 typedef int (*ntfs_collate_func_t)(ntfs_volume *, const void *, const int, 70 const void *, const int); 71 72 static ntfs_collate_func_t ntfs_do_collate0x0[3] = { 73 ntfs_collate_binary, 74 NULL/*ntfs_collate_file_name*/, 75 NULL/*ntfs_collate_unicode_string*/, 76 }; 77 78 static ntfs_collate_func_t ntfs_do_collate0x1[4] = { 79 ntfs_collate_ntofs_ulong, 80 NULL/*ntfs_collate_ntofs_sid*/, 81 NULL/*ntfs_collate_ntofs_security_hash*/, 82 NULL/*ntfs_collate_ntofs_ulongs*/, 83 }; 84 85 /** 86 * ntfs_collate - collate two data items using a specified collation rule 87 * @vol: ntfs volume to which the data items belong 88 * @cr: collation rule to use when comparing the items 89 * @data1: first data item to collate 90 * @data1_len: length in bytes of @data1 91 * @data2: second data item to collate 92 * @data2_len: length in bytes of @data2 93 * 94 * Collate the two data items @data1 and @data2 using the collation rule @cr 95 * and return -1, 0, ir 1 if @data1 is found, respectively, to collate before, 96 * to match, or to collate after @data2. 97 * 98 * For speed we use the collation rule @cr as an index into two tables of 99 * function pointers to call the appropriate collation function. 100 */ 101 int ntfs_collate(ntfs_volume *vol, COLLATION_RULE cr, 102 const void *data1, const int data1_len, 103 const void *data2, const int data2_len) { 104 int i; 105 106 ntfs_debug("Entering."); 107 /* 108 * FIXME: At the moment we only support COLLATION_BINARY and 109 * COLLATION_NTOFS_ULONG, so we BUG() for everything else for now. 110 */ 111 BUG_ON(cr != COLLATION_BINARY && cr != COLLATION_NTOFS_ULONG); 112 i = le32_to_cpu(cr); 113 BUG_ON(i < 0); 114 if (i <= 0x02) 115 return ntfs_do_collate0x0[i](vol, data1, data1_len, 116 data2, data2_len); 117 BUG_ON(i < 0x10); 118 i -= 0x10; 119 if (likely(i <= 3)) 120 return ntfs_do_collate0x1[i](vol, data1, data1_len, 121 data2, data2_len); 122 BUG(); 123 return 0; 124 } 125