collate.c revision 7e7bd3dccbfe8f79e25e5c1554b5bc3a9aaca321
/**
* collate.c - NTFS collation handling. Part of the Linux-NTFS project.
*
* Copyright (c) 2004 Anton Altaparmakov
* Copyright (c) 2005 Yura Pakhuchiy
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the Linux-NTFS
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include "collate.h"
#include "debug.h"
#include "unistr.h"
#include "logging.h"
/**
* ntfs_collate_binary - Which of two binary objects should be listed first
* @vol: unused
* @data1:
* @data1_len:
* @data2:
* @data2_len:
*
* Description...
*
* Returns:
*/
static int ntfs_collate_binary(ntfs_volume *vol __attribute__((unused)),
const void *data1, size_t data1_len,
const void *data2, size_t data2_len)
{
int rc;
ntfs_log_trace("Entering.\n");
rc = memcmp(data1, data2, min(data1_len, data2_len));
if (!rc && (data1_len != data2_len)) {
if (data1_len < data2_len)
rc = -1;
else
rc = 1;
}
ntfs_log_trace("Done, returning %i.\n", rc);
return rc;
}
/**
* ntfs_collate_ntofs_ulong - Which of two long ints should be listed first
* @vol: unused
* @data1:
* @data1_len:
* @data2:
* @data2_len:
*
* Description...
*
* Returns:
*/
static int ntfs_collate_ntofs_ulong(ntfs_volume *vol __attribute__((unused)),
const void *data1, size_t data1_len,
const void *data2, size_t data2_len)
{
int rc;
u32 d1, d2;
ntfs_log_trace("Entering.\n");
if (data1_len != data2_len || data1_len != 4) {
ntfs_log_error("data1_len or/and data2_len not equal to 4.\n");
return NTFS_COLLATION_ERROR;
}
d1 = le32_to_cpup(data1);
d2 = le32_to_cpup(data2);
if (d1 < d2)
rc = -1;
else {
if (d1 == d2)
rc = 0;
else
rc = 1;
}
ntfs_log_trace("Done, returning %i.\n", rc);
return rc;
}
/**
* ntfs_collate_file_name - Which of two filenames should be listed first
* @vol:
* @data1:
* @data1_len: unused
* @data2:
* @data2_len: unused
*
* Description...
*
* Returns:
*/
static int ntfs_collate_file_name(ntfs_volume *vol,
const void *data1, size_t data1_len __attribute__((unused)),
const void *data2, size_t data2_len __attribute__((unused)))
{
int rc;
ntfs_log_trace("Entering.\n");
rc = ntfs_file_values_compare(data1, data2, NTFS_COLLATION_ERROR,
IGNORE_CASE, vol->upcase, vol->upcase_len);
if (!rc)
rc = ntfs_file_values_compare(data1, data2,
NTFS_COLLATION_ERROR, CASE_SENSITIVE,
vol->upcase, vol->upcase_len);
ntfs_log_trace("Done, returning %i.\n", rc);
return rc;
}
typedef int (*ntfs_collate_func_t)(ntfs_volume *, const void *, size_t,
const void *, size_t);
static ntfs_collate_func_t ntfs_do_collate0x0[3] = {
ntfs_collate_binary,
ntfs_collate_file_name,
NULL/*ntfs_collate_unicode_string*/,
};
static ntfs_collate_func_t ntfs_do_collate0x1[4] = {
ntfs_collate_ntofs_ulong,
NULL/*ntfs_collate_ntofs_sid*/,
NULL/*ntfs_collate_ntofs_security_hash*/,
NULL/*ntfs_collate_ntofs_ulongs*/,
};
/**
* ntfs_is_collation_rule_supported - Check if a collation rule is implemented.
* @cr: The to-be-checked collation rule
*
* Use this function to know if @cr is supported by libntfs.
*
* 7 collation rules are known to be supported by NTFS as defined
* in layout.h. However, libntfs only support 3 of them ATM.
*
* Return TRUE if @cr is supported. FALSE otherwise.
*/
BOOL ntfs_is_collation_rule_supported(COLLATION_RULES cr)
{
return (cr == COLLATION_BINARY || cr == COLLATION_NTOFS_ULONG ||
cr == COLLATION_FILE_NAME);
/*
* FIXME: At the moment we only support COLLATION_BINARY,
* COLLATION_NTOFS_ULONG and COLLATION_FILE_NAME.
* The correct future implementation of this function should be:
*
* u32 i = le32_to_cpu(cr);
* return ((i <= 0x02) || ((i >= 0x10) && (i <= 0x13)));
*/
}
/**
* ntfs_collate - collate two data items using a specified collation rule
* @vol: ntfs volume to which the data items belong
* @cr: collation rule to use when comparing the items
* @data1: first data item to collate
* @data1_len: length in bytes of @data1
* @data2: second data item to collate
* @data2_len: length in bytes of @data2
*
* Collate the two data items @data1 and @data2 using the collation rule @cr
* and return -1, 0, or 1 if @data1 is found, respectively, to collate before,
* to match, or to collate after @data2.
*
* For speed we use the collation rule @cr as an index into two tables of
* function pointers to call the appropriate collation function.
*
* Return NTFS_COLLATION_ERROR if error occurred.
*/
int ntfs_collate(ntfs_volume *vol, COLLATION_RULES cr,
const void *data1, size_t data1_len,
const void *data2, size_t data2_len)
{
u32 i;
ntfs_log_trace("Entering.\n");
if (!vol || !data1 || !data2) {
ntfs_log_error("Invalid arguments passed.\n");
return NTFS_COLLATION_ERROR;
}
if (!ntfs_is_collation_rule_supported(cr))
goto err;
i = le32_to_cpu(cr);
if (i <= 0x02)
return ntfs_do_collate0x0[i](vol, data1, data1_len,
data2, data2_len);
if (i < 0x10)
goto err;
i -= 0x10;
if (i <= 3)
return ntfs_do_collate0x1[i](vol, data1, data1_len,
data2, data2_len);
err:
ntfs_log_debug("Unknown collation rule.\n");
return NTFS_COLLATION_ERROR;
}