1/*
2 * Copyright (c) 2000, 2002-2003, 2005-2008 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28#ifndef __HFS_ENDIAN_H__
29#define __HFS_ENDIAN_H__
30
31#include <sys/appleapiopts.h>
32
33#ifdef KERNEL
34#ifdef __APPLE_API_PRIVATE
35/*
36 * hfs_endian.h
37 *
38 * This file prototypes endian swapping routines for the HFS/HFS Plus
39 * volume format.
40 */
41#include "hfs.h"
42#include "hfscommon/headers/BTreesInternal.h"
43#include <libkern/OSByteOrder.h>
44
45/*********************/
46/* BIG ENDIAN Macros */
47/*********************/
48#define SWAP_BE16(__a) 							OSSwapBigToHostInt16 (__a)
49#define SWAP_BE32(__a) 							OSSwapBigToHostInt32 (__a)
50#define SWAP_BE64(__a) 							OSSwapBigToHostInt64 (__a)
51
52#if BYTE_ORDER == BIG_ENDIAN
53
54    /* HFS is always big endian, no swapping needed */
55    #define SWAP_HFS_PLUS_FORK_DATA(__a)
56
57/************************/
58/* LITTLE ENDIAN Macros */
59/************************/
60#elif BYTE_ORDER == LITTLE_ENDIAN
61
62    #define SWAP_HFS_PLUS_FORK_DATA(__a)			hfs_swap_HFSPlusForkData ((__a))
63
64#else
65#warning Unknown byte order
66#error
67#endif
68
69#ifdef __cplusplus
70extern "C" {
71#endif
72
73/*
74 * Constants for the "unswap" argument to hfs_swap_BTNode:
75 */
76enum HFSBTSwapDirection {
77	kSwapBTNodeBigToHost		=	0,
78	kSwapBTNodeHostToBig		=	1,
79
80	/*
81	 * kSwapBTNodeHeaderRecordOnly is used to swap just the header record
82	 * of a header node from big endian (on disk) to host endian (in memory).
83	 * It does not swap the node descriptor (forward/backward links, record
84	 * count, etc.).  It assumes the header record is at offset 0x000E.
85	 *
86	 * Since HFS Plus doesn't have fixed B-tree node sizes, we have to read
87	 * the header record to determine the actual node size for that tree
88	 * before we can set up the B-tree control block.  We read it initially
89	 * as 512 bytes, then re-read it once we know the correct node size.  Since
90	 * we may not have read the entire header node the first time, we can't
91	 * swap the record offsets, other records, or do most sanity checks.
92	 */
93	kSwapBTNodeHeaderRecordOnly	=	3
94};
95
96int  hfs_swap_BTNode (BlockDescriptor *src, vnode_t vp, enum HFSBTSwapDirection direction,
97	u_int8_t allow_empty_node);
98
99#ifdef __cplusplus
100}
101#endif
102
103#endif /* __APPLE_API_PRIVATE */
104#endif /* KERNEL */
105#endif /* __HFS_FORMAT__ */
106