Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

Open Menu /fs/ntfs/collate.c 
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * collate.c - NTFS kernel collation handling.  Part of the Linux-NTFS project.
 *
 * Copyright (c) 2004 Anton Altaparmakov
 */

#include "collate.h"
#include "debug.h"
#include "ntfs.h"

static int ntfs_collate_binary(ntfs_volume *vol,
		const void *data1, const int data1_len,
		const void *data2, const int data2_len)
{
	int rc;

	ntfs_debug("Entering.");
	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_debug("Done, returning %i", rc);
	return rc;
}

static int ntfs_collate_ntofs_ulong(ntfs_volume *vol,
		const void *data1, const int data1_len,
		const void *data2, const int data2_len)
{
	int rc;
	u32 d1, d2;

	ntfs_debug("Entering.");
	// FIXME:  We don't really want to bug here.
	BUG_ON(data1_len != data2_len);
	BUG_ON(data1_len != 4);
	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_debug("Done, returning %i", rc);
	return rc;
}

typedef int (*ntfs_collate_func_t)(ntfs_volume *, const void *, const int,
		const void *, const int);

static ntfs_collate_func_t ntfs_do_collate0x0[3] = {
	ntfs_collate_binary,
	NULL/*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_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, ir 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.
 */
int ntfs_collate(ntfs_volume *vol, COLLATION_RULE cr,
		const void *data1, const int data1_len,
		const void *data2, const int data2_len) {
	int i;

	ntfs_debug("Entering.");
	/*
	 * FIXME:  At the moment we only support COLLATION_BINARY and
	 * COLLATION_NTOFS_ULONG, so we BUG() for everything else for now.
	 */
	BUG_ON(cr != COLLATION_BINARY && cr != COLLATION_NTOFS_ULONG);
	i = le32_to_cpu(cr);
	BUG_ON(i < 0);
	if (i <= 0x02)
		return ntfs_do_collate0x0[i](vol, data1, data1_len,
				data2, data2_len);
	BUG_ON(i < 0x10);
	i -= 0x10;
	if (likely(i <= 3))
		return ntfs_do_collate0x1[i](vol, data1, data1_len,
				data2, data2_len);
	BUG();
	return 0;
}