1 /*        $NetBSD: extattr.h,v 1.12 2020/04/18 19:18:34 christos Exp $          */
2 
3 /*-
4  * Copyright (c) 1999-2001 Robert N. M. Watson
5  * All rights reserved.
6  *
7  * This software was developed by Robert Watson for the TrustedBSD Project.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD: src/sys/ufs/ufs/extattr.h,v 1.20 2005/01/31 08:16:45 imp Exp $
31  */
32 
33 /*
34  * Support for file system extended attributes on the UFS1 file system.
35  * Developed by the TrustedBSD Project.
36  */
37 
38 #ifndef _UFS_UFS_EXTATTR_H_
39 #define   _UFS_UFS_EXTATTR_H_
40 
41 #define   UFS_EXTATTR_MAGIC             0x00b5d5ec
42 #define   UFS_EXTATTR_VERSION           0x00000003
43 #define   UFS_EXTATTR_FSROOTSUBDIR      ".attribute"
44 #define   UFS_EXTATTR_SUBDIR_SYSTEM     "system"
45 #define   UFS_EXTATTR_SUBDIR_USER                 "user"
46 #define   UFS_EXTATTR_MAXEXTATTRNAME    256       /* including null */
47 
48 #define   UFS_EXTATTR_ATTR_FLAG_INUSE   0x00000001          /* attr has been set */
49 #define   UFS_EXTATTR_PERM_KERNEL                 0x00000000
50 #define   UFS_EXTATTR_PERM_ROOT                   0x00000001
51 #define   UFS_EXTATTR_PERM_OWNER                  0x00000002
52 #define   UFS_EXTATTR_PERM_ANYONE                 0x00000003
53 
54 #define   UFS_EXTATTR_UEPM_INITIALIZED  0x00000001
55 #define   UFS_EXTATTR_UEPM_STARTED      0x00000002
56 
57 #define   UFS_EXTATTR_CMD_START                   EXTATTR_CMD_START
58 #define   UFS_EXTATTR_CMD_STOP                    EXTATTR_CMD_STOP
59 #define   UFS_EXTATTR_CMD_ENABLE                  0x00000003
60 #define   UFS_EXTATTR_CMD_DISABLE                 0x00000004
61 
62 struct ufs_extattr_fileheader {
63           uint32_t  uef_magic;          /* magic number for sanity checking */
64           uint32_t  uef_version;        /* version of attribute file */
65           uint32_t  uef_size; /* size of attributes, w/o header */
66 };
67 
68 struct ufs_extattr_header {
69           uint32_t  ueh_flags;          /* flags for attribute */
70           uint32_t  ueh_len;  /* local defined length; <= uef_size */
71           uint32_t  ueh_i_gen;          /* generation number for sanity */
72           /* data follows the header */
73 };
74 
75 /*
76  * This structure defines the required fields of an extended-attribute header.
77  */
78 struct extattr {
79           uint32_t ea_length;     /* length of this attribute */
80           uint8_t   ea_namespace;           /* name space of this attribute */
81           uint8_t   ea_contentpadlen;   /* bytes of padding at end of attribute */
82           uint8_t   ea_namelength;          /* length of attribute name */
83           char      ea_name[1];             /* attribute name (NOT nul-terminated) */
84           /* padding, if any, to align attribute content to 8 byte boundary */
85           /* extended attribute content follows */
86 };
87 
88 /*
89  * These macros are used to access and manipulate an extended attribute:
90  *
91  * EXTATTR_NEXT(eap) returns a pointer to the next extended attribute
92  *        following eap.
93  * EXTATTR_CONTENT(eap) returns a pointer to the extended attribute
94  *        content referenced by eap.
95  * EXTATTR_CONTENT_SIZE(eap) returns the size of the extended attribute
96  *        content referenced by eap.
97  */
98 #define   EXTATTR_NEXT(eap) \
99           ((struct extattr *)(((u_char *)(eap)) + (eap)->ea_length))
100 #define   EXTATTR_CONTENT(eap) \
101           (void *)(((u_char *)(eap)) + EXTATTR_BASE_LENGTH(eap))
102 #define   EXTATTR_CONTENT_SIZE(eap) \
103           ((eap)->ea_length - EXTATTR_BASE_LENGTH(eap) - (eap)->ea_contentpadlen)
104 /* -1 below compensates for ea_name[1] */
105 #define   EXTATTR_BASE_LENGTH(eap) \
106           roundup2((sizeof(struct extattr) - 1 + (eap)->ea_namelength), 8)
107 
108 #ifdef _KERNEL
109 
110 #ifdef MALLOC_DECLARE
111 MALLOC_DECLARE(M_EXTATTR);
112 #endif
113 
114 struct vnode;
115 LIST_HEAD(ufs_extattr_list_head, ufs_extattr_list_entry);
116 struct ufs_extattr_list_entry {
117           LIST_ENTRY(ufs_extattr_list_entry)      uele_entries;
118           struct ufs_extattr_fileheader           uele_fileheader;
119           int                 uele_attrnamespace;
120           char                uele_attrname[UFS_EXTATTR_MAXEXTATTRNAME];
121           struct vnode        *uele_backing_vnode;
122           int                 uele_flags;
123 };
124 
125 /* uele_flags */
126 #define   UELE_F_NEEDSWAP               0x01      /* needs byte swap */
127 
128 #define   UELE_NEEDSWAP(uele) ((uele)->uele_flags & UELE_F_NEEDSWAP)
129 
130 struct lock;
131 struct ufs_extattr_per_mount {
132           kmutex_t                      uepm_lock;
133           struct ufs_extattr_list_head  uepm_list;
134           kauth_cred_t                            uepm_ucred;
135           int                                     uepm_lockcnt;
136           int                                     uepm_flags;
137 };
138 
139 void      ufs_extattr_uepm_init(struct ufs_extattr_per_mount *uepm);
140 void      ufs_extattr_uepm_destroy(struct ufs_extattr_per_mount *uepm);
141 int       ufs_extattr_start(struct mount *mp, struct lwp *l);
142 int       ufs_extattr_autostart(struct mount *mp, struct lwp *l);
143 void      ufs_extattr_stop(struct mount *mp, struct lwp *l);
144 int       ufs_extattrctl(struct mount *mp, int cmd, struct vnode *filename,
145               int attrnamespace, const char *attrname);
146 struct vop_getextattr_args;
147 int       ufs_getextattr(struct vop_getextattr_args *ap);
148 struct vop_deleteextattr_args;
149 int       ufs_deleteextattr(struct vop_deleteextattr_args *ap);
150 struct vop_setextattr_args;
151 int       ufs_setextattr(struct vop_setextattr_args *ap);
152 struct vop_listextattr_args;
153 int       ufs_listextattr(struct vop_listextattr_args *ap);
154 void      ufs_extattr_vnode_inactive(struct vnode *vp, struct lwp *l);
155 
156 void      ufs_extattr_init(void);
157 void      ufs_extattr_done(void);
158 
159 #endif /* !_KERNEL */
160 
161 #endif /* !_UFS_UFS_EXTATTR_H_ */
162