2 * Copyright (c) 2001-2002,2004 Silicon Graphics, Inc.
5 * This program is free software: you can redistribute it and/or modify it
6 * under the terms of the GNU Lesser General Public License as published by
7 * the Free Software Foundation, either version 2.1 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 #ifndef __ATTRIBUTES_H__
19 #define __ATTRIBUTES_H__
26 * An almost-IRIX-compatible extended attributes API
27 * (the IRIX attribute "list" operation is missing, added ATTR_SECURE).
31 * The maximum size (into the kernel or returned from the kernel) of an
32 * attribute value or the buffer used for an attr_list() call. Larger
33 * sizes will result in an E2BIG return code.
35 #define ATTR_MAX_VALUELEN (64*1024) /* max length of a value */
39 * Flags that can be used with any of the simple attribute calls.
40 * All desired flags should be bit-wise OR'ed together.
42 #define ATTR_DONTFOLLOW 0x0001 /* do not follow symlinks for a pathname */
43 #define ATTR_ROOT 0x0002 /* use root namespace attributes in op */
44 #define ATTR_TRUST 0x0004 /* tell server we can be trusted to properly
45 handle extended attributes */
46 #define ATTR_SECURE 0x0008 /* use security namespace attributes in op */
49 * Additional flags that can be used with the set() attribute call.
50 * All desired flags (from both lists) should be bit-wise OR'ed together.
52 #define ATTR_CREATE 0x0010 /* pure create: fail if attr already exists */
53 #define ATTR_REPLACE 0x0020 /* pure set: fail if attr does not exist */
56 * Define how lists of attribute names are returned to the user from
57 * the attr_list() call. A large, 32bit aligned, buffer is passed in
58 * along with its size. We put an array of offsets at the top that each
59 * reference an attrlist_ent_t and pack the attrlist_ent_t's at the bottom.
61 typedef struct attrlist {
62 int32_t al_count; /* number of entries in attrlist */
63 int32_t al_more; /* T/F: more attrs (do call again) */
64 int32_t al_offset[1]; /* byte offsets of attrs [var-sized] */
68 * Show the interesting info about one attribute. This is what the
69 * al_offset[i] entry points to.
71 typedef struct attrlist_ent { /* data from attr_list() */
72 u_int32_t a_valuelen; /* number bytes in value of attr */
73 char a_name[1]; /* attr name (NULL terminated) */
77 * Given a pointer to the (char*) buffer containing the attr_list() result,
78 * and an index, return a pointer to the indicated attribute in the buffer.
80 #define ATTR_ENTRY(buffer, index) \
82 &((char *)buffer)[ ((attrlist_t *)(buffer))->al_offset[index] ])
85 * Implement a "cursor" for use in successive attr_list() calls.
86 * It provides a way to find the last attribute that was returned in the
87 * last attr_list() call so that we can get the next one without missing
88 * any. This should be bzero()ed before use and whenever it is desired to
89 * start over from the beginning of the attribute list. The only valid
90 * operation on a cursor is to bzero() it.
92 typedef struct attrlist_cursor {
93 u_int32_t opaque[4]; /* an opaque cookie */
97 * Multi-attribute operation vector.
99 typedef struct attr_multiop {
100 int32_t am_opcode; /* operation to perform (ATTR_OP_GET, etc.) */
101 int32_t am_error; /* [out arg] result of this sub-op (an errno) */
102 char *am_attrname; /* attribute name to work with */
103 char *am_attrvalue; /* [in/out arg] attribute value (raw bytes) */
104 int32_t am_length; /* [in/out arg] length of value */
105 int32_t am_flags; /* flags (bit-wise OR of #defines above) */
107 #define ATTR_MAX_MULTIOPS 128 /* max number ops in an oplist array */
110 * Valid values of am_opcode.
112 #define ATTR_OP_GET 1 /* return the indicated attr's value */
113 #define ATTR_OP_SET 2 /* set/create the indicated attr/value pair */
114 #define ATTR_OP_REMOVE 3 /* remove the indicated attr */
117 * Get the value of an attribute.
118 * Valuelength must be set to the maximum size of the value buffer, it will
119 * be set to the actual number of bytes used in the value buffer upon return.
120 * The return value is -1 on error (w/errno set appropriately), 0 on success.
122 extern int attr_get (const char *__path, const char *__attrname,
123 char *__attrvalue, int *__valuelength, int __flags);
124 extern int attr_getf (int __fd, const char *__attrname, char *__attrvalue,
125 int *__valuelength, int __flags);
128 * Set the value of an attribute, creating the attribute if necessary.
129 * The return value is -1 on error (w/errno set appropriately), 0 on success.
131 extern int attr_set (const char *__path, const char *__attrname,
132 const char *__attrvalue, const int __valuelength,
134 extern int attr_setf (int __fd, const char *__attrname,
135 const char *__attrvalue, const int __valuelength,
139 * Remove an attribute.
140 * The return value is -1 on error (w/errno set appropriately), 0 on success.
142 extern int attr_remove (const char *__path, const char *__attrname,
144 extern int attr_removef (int __fd, const char *__attrname, int __flags);
147 * List the names and sizes of the values of all the attributes of an object.
148 * "Cursor" must be allocated and zeroed before the first call, it is used
149 * to maintain context between system calls if all the attribute names won't
150 * fit into the buffer on the first system call.
151 * The return value is -1 on error (w/errno set appropriately), 0 on success.
153 int attr_list(const char *__path, char *__buffer, const int __buffersize,
154 int __flags, attrlist_cursor_t *__cursor);
155 int attr_listf(int __fd, char *__buffer, const int __buffersize,
156 int __flags, attrlist_cursor_t *__cursor);
159 * Operate on multiple attributes of the same object simultaneously.
161 * This call will save on system call overhead when many attributes are
162 * going to be operated on.
164 * The return value is -1 on error (w/errno set appropriately), 0 on success.
165 * Note that this call will not return -1 as a result of failure of any
166 * of the sub-operations, their return value is stored in each element
167 * of the operation array. This call will return -1 for a failure of the
168 * call as a whole, eg: if the pathname doesn't exist, or the fd is bad.
170 * The semantics and allowable values for the fields in a attr_multiop_t
171 * are the same as the semantics and allowable values for the arguments to
172 * the corresponding "simple" attribute interface. For example: the args
173 * to a ATTR_OP_GET are the same as the args to an attr_get() call.
175 extern int attr_multi (const char *__path, attr_multiop_t *__oplist,
176 int __count, int __flags);
177 extern int attr_multif (int __fd, attr_multiop_t *__oplist,
178 int __count, int __flags);
184 #endif /* __ATTRIBUTES_H__ */