xref: /netbsd-src/sys/ufs/ext2fs/ext2fs_xattr.h (revision 72d26a2dda23791b892cf8f1f49376e5de407c78)
1 /*	$NetBSD: ext2fs_xattr.h,v 1.4 2020/04/16 23:29:53 rin Exp $	*/
2 
3 /*-
4  * Copyright (c) 2016 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jaromir Dolecek.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _UFS_EXT2FS_EXT2FS_XATTR_H_
33 #define _UFS_EXT2FS_EXT2FS_XATTR_H_
34 
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: ext2fs_xattr.h,v 1.4 2020/04/16 23:29:53 rin Exp $");
37 
38 #ifdef _KERNEL
39 
40 #define EXT2FS_XATTR_MAGIC 	0xEA020000
41 
42 #define EXT2FS_XATTR_NAME_LEN_MAX	255
43 #define EXT2FS_XATTR_REFCOUNT_MAX	1024
44 
45 /*
46  * This is used as header for extended attribute block within inode
47  */
48 struct ext2fs_xattr_ibody_header {
49 	uint32_t h_magic;	/* Magic number - 0xEA020000 */
50 };
51 
52 /*
53  * This is used as header for extended attribute on separate disk block
54  */
55 struct ext2fs_xattr_header {
56 	uint32_t h_magic;	/* Magic number - 0xEA020000 */
57 	uint32_t h_refcount;	/* Reference count */
58 	uint32_t h_blocks;	/* Number of blocks - only 1 supported */
59 	uint32_t h_hash;	/* Hash of all attributes */
60  	uint32_t h_checksum;	/* Checksum of the extended attribute block */
61 	uint32_t h_reserved[3];
62 };
63 
64 /*
65  * Extended attribute on-disk header structure
66  */
67 struct ext2fs_xattr_entry {
68         uint8_t  e_name_len;		/* Name length */
69         uint8_t  e_name_index;		/* Name prefix index (see below) */
70         uint16_t e_value_offs;		/* Offset of value within block */
71         uint32_t e_value_block;		/* Value block - not supported (always zero) */
72         uint32_t e_value_size;		/* Length of value */
73         uint32_t e_hash;		/* Hash (not supported) */
74         char e_name[0];			/* Name string (e_name_len bytes) */
75 };
76 
77 /*
78  * Linux kernel checks only the 0, we also check that the current entry
79  * doesn't overflow past end.
80  */
81 #define EXT2FS_XATTR_IS_LAST_ENTRY(entry, end) \
82 	(*((uint32_t *)(entry)) == 0 || (uintptr_t)EXT2FS_XATTR_NEXT(entry) > (uintptr_t)end)
83 
84 /*
85  * Each ext2fs_xattr_entry starts on next 4-byte boundary, pad if necessary.
86  */
87 #define EXT2FS_XATTR_PAD	4
88 #define EXT2FS_XATTR_ROUND	(EXT2FS_XATTR_PAD - 1)
89 #define EXT2FS_XATTR_LEN(name_len) \
90 	(((name_len) + EXT2FS_XATTR_ROUND + \
91 	sizeof(struct ext2fs_xattr_entry)) & ~EXT2FS_XATTR_ROUND)
92 #define EXT2FS_XATTR_NEXT(entry) \
93 	(struct ext2fs_xattr_entry *)(((uint8_t *)(entry)) + EXT2FS_XATTR_LEN((entry)->e_name_len))
94 
95 #define EXT2FS_XATTR_IFIRST(h) (void *)&(h)[1]
96 #define EXT2FS_XATTR_BFIRST(h) EXT2FS_XATTR_IFIRST(h)
97 
98 /*
99  * Name prefixes
100  */
101 #define EXT2FS_XATTR_PREFIX_NONE		0 /* no prefix */
102 #define EXT2FS_XATTR_PREFIX_USER		1 /* "user." */
103 #define EXT2FS_XATTR_PREFIX_POSIX_ACCESS	2 /* "system.posix_acl_access" */
104 #define EXT2FS_XATTR_PREFIX_POSIX_DEFAULT1	3 /* "system.posix_acl_default" */
105 #define EXT2FS_XATTR_PREFIX_TRUSTED		4 /* "trusted." */
106 #define EXT2FS_XATTR_PREFIX_SECURITY		6 /* "security." */
107 #define EXT2FS_XATTR_PREFIX_SYSTEM		7 /* "system." */
108 #define EXT2FS_XATTR_PREFIX_SYSTEM_RICHACL	8 /* "system.richacl" */
109 #define EXT2FS_XATTR_PREFIX_ENCRYPTION		9 /* "c" */
110 
111 int ext2fs_getextattr(void *);
112 int ext2fs_setextattr(void *);
113 int ext2fs_listextattr(void *);
114 int ext2fs_deleteextattr(void *);
115 #endif /* _KERNEL */
116 
117 #endif /* _UFS_EXT2FS_EXT2FS_XATTR_H_ */
118