xref: /freebsd/sys/ufs/ufs/extattr.h (revision a0ee8cc6)
1 /*-
2  * Copyright (c) 1999-2001 Robert N. M. Watson
3  * All rights reserved.
4  *
5  * This software was developed by Robert Watson for the TrustedBSD Project.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 /*
31  * Developed by the TrustedBSD Project.
32  * Support for extended filesystem attributes.
33  */
34 
35 #ifndef _UFS_UFS_EXTATTR_H_
36 #define	_UFS_UFS_EXTATTR_H_
37 
38 #define	UFS_EXTATTR_MAGIC		0x00b5d5ec
39 #define	UFS_EXTATTR_VERSION		0x00000003
40 #define	UFS_EXTATTR_FSROOTSUBDIR	".attribute"
41 #define	UFS_EXTATTR_SUBDIR_SYSTEM	"system"
42 #define	UFS_EXTATTR_SUBDIR_USER		"user"
43 #define	UFS_EXTATTR_MAXEXTATTRNAME	65	/* including null */
44 
45 #define	UFS_EXTATTR_ATTR_FLAG_INUSE	0x00000001	/* attr has been set */
46 #define	UFS_EXTATTR_PERM_KERNEL		0x00000000
47 #define	UFS_EXTATTR_PERM_ROOT		0x00000001
48 #define	UFS_EXTATTR_PERM_OWNER		0x00000002
49 #define	UFS_EXTATTR_PERM_ANYONE		0x00000003
50 
51 #define	UFS_EXTATTR_UEPM_INITIALIZED	0x00000001
52 #define	UFS_EXTATTR_UEPM_STARTED	0x00000002
53 
54 #define	UFS_EXTATTR_CMD_START		0x00000001
55 #define	UFS_EXTATTR_CMD_STOP		0x00000002
56 #define	UFS_EXTATTR_CMD_ENABLE		0x00000003
57 #define	UFS_EXTATTR_CMD_DISABLE		0x00000004
58 
59 struct ufs_extattr_fileheader {
60 	u_int	uef_magic;	/* magic number for sanity checking */
61 	u_int	uef_version;	/* version of attribute file */
62 	u_int	uef_size;	/* size of attributes, w/o header */
63 };
64 
65 struct ufs_extattr_header {
66 	u_int	ueh_flags;	/* flags for attribute */
67 	u_int	ueh_len;	/* local defined length; <= uef_size */
68 	u_int32_t	ueh_i_gen;	/* generation number for sanity */
69 	/* data follows the header */
70 };
71 
72 /*
73  * This structure defines the required fields of an extended-attribute header.
74  */
75 struct extattr {
76 	int32_t	ea_length;	    /* length of this attribute */
77 	int8_t	ea_namespace;	    /* name space of this attribute */
78 	int8_t	ea_contentpadlen;   /* bytes of padding at end of attribute */
79 	int8_t	ea_namelength;	    /* length of attribute name */
80 	char	ea_name[1];	    /* null-terminated attribute name */
81 	/* extended attribute content follows */
82 };
83 
84 /*
85  * These macros are used to access and manipulate an extended attribute:
86  *
87  * EXTATTR_NEXT(eap) returns a pointer to the next extended attribute
88  *	following eap.
89  * EXTATTR_CONTENT(eap) returns a pointer to the extended attribute
90  *	content referenced by eap.
91  * EXTATTR_CONTENT_SIZE(eap) returns the size of the extended attribute
92  *	content referenced by eap.
93  * EXTATTR_SET_LENGTHS(eap, contentsize) called after initializing the
94  *	attribute name to calculate and set the ea_length, ea_namelength,
95  *	and ea_contentpadlen fields of the extended attribute structure.
96  */
97 #define	EXTATTR_NEXT(eap) \
98 	((struct extattr *)(((void *)(eap)) + (eap)->ea_length))
99 #define	EXTATTR_CONTENT(eap) (((void *)(eap)) + EXTATTR_BASE_LENGTH(eap))
100 #define	EXTATTR_CONTENT_SIZE(eap) \
101 	((eap)->ea_length - EXTATTR_BASE_LENGTH(eap) - (eap)->ea_contentpadlen)
102 #define	EXTATTR_BASE_LENGTH(eap) \
103 	((sizeof(struct extattr) + (eap)->ea_namelength + 7) & ~7)
104 #define	EXTATTR_SET_LENGTHS(eap, contentsize) do { \
105 	KASSERT(((eap)->ea_name[0] != 0), \
106 		("Must initialize name before setting lengths")); \
107 	(eap)->ea_namelength = strlen((eap)->ea_name); \
108 	(eap)->ea_contentpadlen = ((contentsize) % 8) ? \
109 		8 - ((contentsize) % 8) : 0; \
110 	(eap)->ea_length = EXTATTR_BASE_LENGTH(eap) + \
111 		(contentsize) + (eap)->ea_contentpadlen; \
112 } while (0)
113 
114 #ifdef _KERNEL
115 
116 #include <sys/_sx.h>
117 
118 struct vnode;
119 LIST_HEAD(ufs_extattr_list_head, ufs_extattr_list_entry);
120 struct ufs_extattr_list_entry {
121 	LIST_ENTRY(ufs_extattr_list_entry)	uele_entries;
122 	struct ufs_extattr_fileheader		uele_fileheader;
123 	int	uele_attrnamespace;
124 	char	uele_attrname[UFS_EXTATTR_MAXEXTATTRNAME];
125 	struct vnode	*uele_backing_vnode;
126 };
127 
128 struct ucred;
129 struct ufs_extattr_per_mount {
130 	struct sx	uepm_lock;
131 	struct ufs_extattr_list_head	uepm_list;
132 	struct ucred	*uepm_ucred;
133 	int	uepm_flags;
134 };
135 
136 void	ufs_extattr_uepm_init(struct ufs_extattr_per_mount *uepm);
137 void	ufs_extattr_uepm_destroy(struct ufs_extattr_per_mount *uepm);
138 int	ufs_extattr_start(struct mount *mp, struct thread *td);
139 int	ufs_extattr_autostart(struct mount *mp, struct thread *td);
140 int	ufs_extattr_stop(struct mount *mp, struct thread *td);
141 int	ufs_extattrctl(struct mount *mp, int cmd, struct vnode *filename,
142 	    int attrnamespace, const char *attrname);
143 int	ufs_getextattr(struct vop_getextattr_args *ap);
144 int	ufs_deleteextattr(struct vop_deleteextattr_args *ap);
145 int	ufs_setextattr(struct vop_setextattr_args *ap);
146 void	ufs_extattr_vnode_inactive(struct vnode *vp, struct thread *td);
147 
148 #else
149 
150 /* User-level definition of KASSERT for macros above */
151 #define	KASSERT(cond, str) do { \
152         if (!(cond)) { printf("panic: "); printf(str); printf("\n"); exit(1); }\
153 } while (0)
154 
155 #endif /* !_KERNEL */
156 
157 #endif /* !_UFS_UFS_EXTATTR_H_ */
158