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124 lines
3.6 KiB
124 lines
3.6 KiB
/* |
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* collate.c - NTFS kernel collation handling. Part of the Linux-NTFS project. |
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* |
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* Copyright (c) 2004 Anton Altaparmakov |
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* |
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* This program/include file is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU General Public License as published |
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* by the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* This program/include file is distributed in the hope that it will be |
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* useful, but WITHOUT ANY WARRANTY; without even the implied warranty |
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program (in the main directory of the Linux-NTFS |
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* distribution in the file COPYING); if not, write to the Free Software |
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* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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#include "collate.h" |
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#include "debug.h" |
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#include "ntfs.h" |
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static int ntfs_collate_binary(ntfs_volume *vol, |
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const void *data1, const int data1_len, |
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const void *data2, const int data2_len) |
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{ |
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int rc; |
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ntfs_debug("Entering."); |
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rc = memcmp(data1, data2, min(data1_len, data2_len)); |
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if (!rc && (data1_len != data2_len)) { |
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if (data1_len < data2_len) |
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rc = -1; |
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else |
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rc = 1; |
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} |
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ntfs_debug("Done, returning %i", rc); |
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return rc; |
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} |
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static int ntfs_collate_ntofs_ulong(ntfs_volume *vol, |
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const void *data1, const int data1_len, |
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const void *data2, const int data2_len) |
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{ |
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int rc; |
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u32 d1, d2; |
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ntfs_debug("Entering."); |
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// FIXME: We don't really want to bug here. |
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BUG_ON(data1_len != data2_len); |
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BUG_ON(data1_len != 4); |
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d1 = le32_to_cpup(data1); |
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d2 = le32_to_cpup(data2); |
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if (d1 < d2) |
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rc = -1; |
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else { |
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if (d1 == d2) |
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rc = 0; |
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else |
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rc = 1; |
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} |
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ntfs_debug("Done, returning %i", rc); |
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return rc; |
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} |
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typedef int (*ntfs_collate_func_t)(ntfs_volume *, const void *, const int, |
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const void *, const int); |
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static ntfs_collate_func_t ntfs_do_collate0x0[3] = { |
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ntfs_collate_binary, |
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NULL/*ntfs_collate_file_name*/, |
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NULL/*ntfs_collate_unicode_string*/, |
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}; |
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static ntfs_collate_func_t ntfs_do_collate0x1[4] = { |
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ntfs_collate_ntofs_ulong, |
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NULL/*ntfs_collate_ntofs_sid*/, |
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NULL/*ntfs_collate_ntofs_security_hash*/, |
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NULL/*ntfs_collate_ntofs_ulongs*/, |
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}; |
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/** |
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* ntfs_collate - collate two data items using a specified collation rule |
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* @vol: ntfs volume to which the data items belong |
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* @cr: collation rule to use when comparing the items |
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* @data1: first data item to collate |
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* @data1_len: length in bytes of @data1 |
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* @data2: second data item to collate |
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* @data2_len: length in bytes of @data2 |
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* |
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* Collate the two data items @data1 and @data2 using the collation rule @cr |
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* and return -1, 0, ir 1 if @data1 is found, respectively, to collate before, |
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* to match, or to collate after @data2. |
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* |
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* For speed we use the collation rule @cr as an index into two tables of |
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* function pointers to call the appropriate collation function. |
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*/ |
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int ntfs_collate(ntfs_volume *vol, COLLATION_RULE cr, |
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const void *data1, const int data1_len, |
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const void *data2, const int data2_len) { |
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int i; |
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ntfs_debug("Entering."); |
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/* |
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* FIXME: At the moment we only support COLLATION_BINARY and |
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* COLLATION_NTOFS_ULONG, so we BUG() for everything else for now. |
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*/ |
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BUG_ON(cr != COLLATION_BINARY && cr != COLLATION_NTOFS_ULONG); |
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i = le32_to_cpu(cr); |
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BUG_ON(i < 0); |
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if (i <= 0x02) |
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return ntfs_do_collate0x0[i](vol, data1, data1_len, |
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data2, data2_len); |
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BUG_ON(i < 0x10); |
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i -= 0x10; |
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if (likely(i <= 3)) |
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return ntfs_do_collate0x1[i](vol, data1, data1_len, |
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data2, data2_len); |
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BUG(); |
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return 0; |
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}
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