2 * sysctl.h: General linux system control interface
4 * Begun 24 March 1995, Stephen Tweedie
6 ****************************************************************
7 ****************************************************************
10 ** The values in this file are exported to user space via
11 ** the sysctl() binary interface. Do *NOT* change the
12 ** numbering of any existing values here, and do not change
13 ** any numbers within any one set of values. If you have to
14 ** redefine an existing interface, use a new number for it.
15 ** The kernel will then return -ENOTDIR to any application using
16 ** the old binary interface.
18 ****************************************************************
19 ****************************************************************
21 #ifndef _LINUX_SYSCTL_H
22 #define _LINUX_SYSCTL_H
24 #include <linux/list.h>
25 #include <linux/rcupdate.h>
26 #include <linux/wait.h>
27 #include <linux/rbtree.h>
28 #include <linux/uidgid.h>
29 #include <uapi/linux/sysctl.h>
31 /* For the /proc/sys support */
35 struct ctl_table_root
;
36 struct ctl_table_header
;
39 typedef int proc_handler (struct ctl_table
*ctl
, int write
,
40 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
42 extern int proc_dostring(struct ctl_table
*, int,
43 void __user
*, size_t *, loff_t
*);
44 extern int proc_dointvec(struct ctl_table
*, int,
45 void __user
*, size_t *, loff_t
*);
46 extern int proc_douintvec(struct ctl_table
*, int,
47 void __user
*, size_t *, loff_t
*);
48 extern int proc_dointvec_minmax(struct ctl_table
*, int,
49 void __user
*, size_t *, loff_t
*);
50 extern int proc_douintvec_minmax(struct ctl_table
*table
, int write
,
51 void __user
*buffer
, size_t *lenp
,
53 extern int proc_dointvec_jiffies(struct ctl_table
*, int,
54 void __user
*, size_t *, loff_t
*);
55 extern int proc_dointvec_userhz_jiffies(struct ctl_table
*, int,
56 void __user
*, size_t *, loff_t
*);
57 extern int proc_dointvec_ms_jiffies(struct ctl_table
*, int,
58 void __user
*, size_t *, loff_t
*);
59 extern int proc_doulongvec_minmax(struct ctl_table
*, int,
60 void __user
*, size_t *, loff_t
*);
61 extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int,
62 void __user
*, size_t *, loff_t
*);
63 extern int proc_do_large_bitmap(struct ctl_table
*, int,
64 void __user
*, size_t *, loff_t
*);
67 * Register a set of sysctl names by calling register_sysctl_table
68 * with an initialised array of struct ctl_table's. An entry with
69 * NULL procname terminates the table. table->de will be
70 * set up by the registration and need not be initialised in advance.
72 * sysctl names can be mirrored automatically under /proc/sys. The
73 * procname supplied controls /proc naming.
75 * The table's mode will be honoured both for sys_sysctl(2) and
78 * Leaf nodes in the sysctl tree will be represented by a single file
79 * under /proc; non-leaf nodes will be represented by directories. A
80 * null procname disables /proc mirroring at this node.
82 * sysctl(2) can automatically manage read and write requests through
83 * the sysctl table. The data and maxlen fields of the ctl_table
84 * struct enable minimal validation of the values being written to be
85 * performed, and the mode field allows minimal authentication.
87 * There must be a proc_handler routine for any terminal nodes
88 * mirrored under /proc/sys (non-terminals are handled by a built-in
89 * directory handler). Several default handlers are available to
93 /* Support for userspace poll() to watch for changes */
94 struct ctl_table_poll
{
96 wait_queue_head_t wait
;
99 static inline void *proc_sys_poll_event(struct ctl_table_poll
*poll
)
101 return (void *)(unsigned long)atomic_read(&poll
->event
);
104 #define __CTL_TABLE_POLL_INITIALIZER(name) { \
105 .event = ATOMIC_INIT(0), \
106 .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }
108 #define DEFINE_CTL_TABLE_POLL(name) \
109 struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name)
111 /* A sysctl table is an array of struct ctl_table: */
114 const char *procname
; /* Text ID for /proc/sys, or zero */
118 struct ctl_table
*child
; /* Deprecated */
119 proc_handler
*proc_handler
; /* Callback for text formatting */
120 struct ctl_table_poll
*poll
;
127 struct ctl_table_header
*header
;
130 /* struct ctl_table_header is used to maintain dynamic lists of
131 struct ctl_table trees. */
132 struct ctl_table_header
136 struct ctl_table
*ctl_table
;
143 struct completion
*unregistering
;
144 struct ctl_table
*ctl_table_arg
;
145 struct ctl_table_root
*root
;
146 struct ctl_table_set
*set
;
147 struct ctl_dir
*parent
;
148 struct ctl_node
*node
;
149 struct hlist_head inodes
; /* head for proc_inode->sysctl_inodes */
153 /* Header must be at the start of ctl_dir */
154 struct ctl_table_header header
;
158 struct ctl_table_set
{
159 int (*is_seen
)(struct ctl_table_set
*);
163 struct ctl_table_root
{
164 struct ctl_table_set default_set
;
165 struct ctl_table_set
*(*lookup
)(struct ctl_table_root
*root
);
166 void (*set_ownership
)(struct ctl_table_header
*head
,
167 struct ctl_table
*table
,
168 kuid_t
*uid
, kgid_t
*gid
);
169 int (*permissions
)(struct ctl_table_header
*head
, struct ctl_table
*table
);
172 /* struct ctl_path describes where in the hierarchy a table is added */
174 const char *procname
;
179 void proc_sys_poll_notify(struct ctl_table_poll
*poll
);
181 extern void setup_sysctl_set(struct ctl_table_set
*p
,
182 struct ctl_table_root
*root
,
183 int (*is_seen
)(struct ctl_table_set
*));
184 extern void retire_sysctl_set(struct ctl_table_set
*set
);
186 struct ctl_table_header
*__register_sysctl_table(
187 struct ctl_table_set
*set
,
188 const char *path
, struct ctl_table
*table
);
189 struct ctl_table_header
*__register_sysctl_paths(
190 struct ctl_table_set
*set
,
191 const struct ctl_path
*path
, struct ctl_table
*table
);
192 struct ctl_table_header
*register_sysctl(const char *path
, struct ctl_table
*table
);
193 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
);
194 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
195 struct ctl_table
*table
);
197 void unregister_sysctl_table(struct ctl_table_header
* table
);
199 extern int sysctl_init(void);
201 extern struct ctl_table sysctl_mount_point
[];
203 #else /* CONFIG_SYSCTL */
204 static inline struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
209 static inline struct ctl_table_header
*register_sysctl_paths(
210 const struct ctl_path
*path
, struct ctl_table
*table
)
215 static inline void unregister_sysctl_table(struct ctl_table_header
* table
)
219 static inline void setup_sysctl_set(struct ctl_table_set
*p
,
220 struct ctl_table_root
*root
,
221 int (*is_seen
)(struct ctl_table_set
*))
225 #endif /* CONFIG_SYSCTL */
227 int sysctl_max_threads(struct ctl_table
*table
, int write
,
228 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
230 #endif /* _LINUX_SYSCTL_H */