1/*
2 * Copyright (c) 2000,2002-2003,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17 */
18#ifndef __XFS_ATTR_H__
19#define	__XFS_ATTR_H__
20
21/*
22 * xfs_attr.h
23 *
24 * Large attribute lists are structured around Btrees where all the data
25 * elements are in the leaf nodes.  Attribute names are hashed into an int,
26 * then that int is used as the index into the Btree.  Since the hashval
27 * of an attribute name may not be unique, we may have duplicate keys.
28 * The internal links in the Btree are logical block offsets into the file.
29 *
30 * Small attribute lists use a different format and are packed as tightly
31 * as possible so as to fit into the literal area of the inode.
32 */
33
34/*========================================================================
35 * External interfaces
36 *========================================================================*/
37
38struct cred;
39struct xfs_vnode;
40
41typedef int (*attrset_t)(struct xfs_vnode *, char *, void *, size_t, int);
42typedef int (*attrget_t)(struct xfs_vnode *, char *, void *, size_t, int);
43typedef int (*attrremove_t)(struct xfs_vnode *, char *, int);
44typedef int (*attrexists_t)(struct xfs_vnode *);
45typedef int (*attrcapable_t)(struct xfs_vnode *, struct cred *);
46
47typedef struct attrnames {
48	char *		attr_name;
49	unsigned int	attr_namelen;
50	unsigned int	attr_flag;
51	attrget_t	attr_get;
52	attrset_t	attr_set;
53	attrremove_t	attr_remove;
54	attrexists_t	attr_exists;
55	attrcapable_t	attr_capable;
56} attrnames_t;
57
58#define ATTR_NAMECOUNT	4
59extern struct attrnames attr_user;
60extern struct attrnames attr_secure;
61extern struct attrnames attr_system;
62extern struct attrnames attr_trusted;
63extern struct attrnames *attr_namespaces[ATTR_NAMECOUNT];
64
65extern attrnames_t *attr_lookup_namespace(char *, attrnames_t **, int);
66extern int attr_generic_list(struct xfs_vnode *, void *, size_t, int, ssize_t *);
67
68#define ATTR_DONTFOLLOW	0x0001	/* -- unused, from IRIX -- */
69#define ATTR_ROOT	0x0002	/* use attrs in root (trusted) namespace */
70#define ATTR_TRUST	0x0004	/* -- unused, from IRIX -- */
71#define ATTR_SECURE	0x0008	/* use attrs in security namespace */
72#define ATTR_CREATE	0x0010	/* pure create: fail if attr already exists */
73#define ATTR_REPLACE	0x0020	/* pure set: fail if attr does not exist */
74#define ATTR_SYSTEM	0x0100	/* use attrs in system (pseudo) namespace */
75
76#define ATTR_KERNACCESS	0x0400	/* [kernel] iaccess, inode held io-locked */
77#define ATTR_KERNOTIME	0x1000	/* [kernel] don't update inode timestamps */
78#define ATTR_KERNOVAL	0x2000	/* [kernel] get attr size only, not value */
79#define ATTR_KERNAMELS	0x4000	/* [kernel] list attr names (simple list) */
80
81#define ATTR_KERNORMALS	0x0800	/* [kernel] normal attr list: user+secure */
82#define ATTR_KERNROOTLS	0x8000	/* [kernel] include root in the attr list */
83#define ATTR_KERNFULLS	(ATTR_KERNORMALS|ATTR_KERNROOTLS)
84
85/*
86 * The maximum size (into the kernel or returned from the kernel) of an
87 * attribute value or the buffer used for an attr_list() call.  Larger
88 * sizes will result in an ERANGE return code.
89 */
90#define	ATTR_MAX_VALUELEN	(64*1024)	/* max length of a value */
91
92/*
93 * Define how lists of attribute names are returned to the user from
94 * the attr_list() call.  A large, 32bit aligned, buffer is passed in
95 * along with its size.  We put an array of offsets at the top that each
96 * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
97 */
98typedef struct attrlist {
99	__s32	al_count;	/* number of entries in attrlist */
100	__s32	al_more;	/* T/F: more attrs (do call again) */
101	__s32	al_offset[1];	/* byte offsets of attrs [var-sized] */
102} attrlist_t;
103
104/*
105 * Show the interesting info about one attribute.  This is what the
106 * al_offset[i] entry points to.
107 */
108typedef struct attrlist_ent {	/* data from attr_list() */
109	__u32	a_valuelen;	/* number bytes in value of attr */
110	char	a_name[1];	/* attr name (NULL terminated) */
111} attrlist_ent_t;
112
113/*
114 * Given a pointer to the (char*) buffer containing the attr_list() result,
115 * and an index, return a pointer to the indicated attribute in the buffer.
116 */
117#define	ATTR_ENTRY(buffer, index)		\
118	((attrlist_ent_t *)			\
119	 &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ])
120
121/*
122 * Multi-attribute operation vector.
123 */
124typedef struct attr_multiop {
125	int	am_opcode;	/* operation to perform (ATTR_OP_GET, etc.) */
126	int	am_error;	/* [out arg] result of this sub-op (an errno) */
127	char	*am_attrname;	/* attribute name to work with */
128	char	*am_attrvalue;	/* [in/out arg] attribute value (raw bytes) */
129	int	am_length;	/* [in/out arg] length of value */
130	int	am_flags;	/* bitwise OR of attr API flags defined above */
131} attr_multiop_t;
132
133#define ATTR_OP_GET	1	/* return the indicated attr's value */
134#define ATTR_OP_SET	2	/* set/create the indicated attr/value pair */
135#define ATTR_OP_REMOVE	3	/* remove the indicated attr */
136
137/*
138 * Kernel-internal version of the attrlist cursor.
139 */
140typedef struct attrlist_cursor_kern {
141	__u32	hashval;	/* hash value of next entry to add */
142	__u32	blkno;		/* block containing entry (suggestion) */
143	__u32	offset;		/* offset in list of equal-hashvals */
144	__u16	pad1;		/* padding to match user-level */
145	__u8	pad2;		/* padding to match user-level */
146	__u8	initted;	/* T/F: cursor has been initialized */
147} attrlist_cursor_kern_t;
148
149
150/*========================================================================
151 * Function prototypes for the kernel.
152 *========================================================================*/
153
154struct xfs_inode;
155struct attrlist_cursor_kern;
156struct xfs_da_args;
157
158/*
159 * Overall external interface routines.
160 */
161int xfs_attr_get(bhv_desc_t *, const char *, char *, int *, int, struct cred *);
162int xfs_attr_set(bhv_desc_t *, const char *, char *, int, int, struct cred *);
163int xfs_attr_remove(bhv_desc_t *, const char *, int, struct cred *);
164int xfs_attr_list(bhv_desc_t *, char *, int, int,
165			 struct attrlist_cursor_kern *, struct cred *);
166int xfs_attr_inactive(struct xfs_inode *dp);
167
168int xfs_attr_shortform_getvalue(struct xfs_da_args *);
169int xfs_attr_fetch(struct xfs_inode *, const char *, int,
170			char *, int *, int, struct cred *);
171
172#endif	/* __XFS_ATTR_H__ */
173