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 <uapi/linux/sysctl.h>
30 /* For the /proc/sys support */
34 struct ctl_table_root
;
35 struct ctl_table_header
;
38 typedef int proc_handler (struct ctl_table
*ctl
, int write
,
39 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
41 extern int proc_dostring(struct ctl_table
*, int,
42 void __user
*, size_t *, loff_t
*);
43 extern int proc_dointvec(struct ctl_table
*, int,
44 void __user
*, size_t *, loff_t
*);
45 extern int proc_dointvec_minmax(struct ctl_table
*, int,
46 void __user
*, size_t *, loff_t
*);
47 extern int proc_dointvec_jiffies(struct ctl_table
*, int,
48 void __user
*, size_t *, loff_t
*);
49 extern int proc_dointvec_userhz_jiffies(struct ctl_table
*, int,
50 void __user
*, size_t *, loff_t
*);
51 extern int proc_dointvec_ms_jiffies(struct ctl_table
*, int,
52 void __user
*, size_t *, loff_t
*);
53 extern int proc_doulongvec_minmax(struct ctl_table
*, int,
54 void __user
*, size_t *, loff_t
*);
55 extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int,
56 void __user
*, size_t *, loff_t
*);
57 extern int proc_do_large_bitmap(struct ctl_table
*, int,
58 void __user
*, size_t *, loff_t
*);
61 * Register a set of sysctl names by calling register_sysctl_table
62 * with an initialised array of struct ctl_table's. An entry with
63 * NULL procname terminates the table. table->de will be
64 * set up by the registration and need not be initialised in advance.
66 * sysctl names can be mirrored automatically under /proc/sys. The
67 * procname supplied controls /proc naming.
69 * The table's mode will be honoured both for sys_sysctl(2) and
72 * Leaf nodes in the sysctl tree will be represented by a single file
73 * under /proc; non-leaf nodes will be represented by directories. A
74 * null procname disables /proc mirroring at this node.
76 * sysctl(2) can automatically manage read and write requests through
77 * the sysctl table. The data and maxlen fields of the ctl_table
78 * struct enable minimal validation of the values being written to be
79 * performed, and the mode field allows minimal authentication.
81 * There must be a proc_handler routine for any terminal nodes
82 * mirrored under /proc/sys (non-terminals are handled by a built-in
83 * directory handler). Several default handlers are available to
87 /* Support for userspace poll() to watch for changes */
88 struct ctl_table_poll
{
90 wait_queue_head_t wait
;
93 static inline void *proc_sys_poll_event(struct ctl_table_poll
*poll
)
95 return (void *)(unsigned long)atomic_read(&poll
->event
);
98 #define __CTL_TABLE_POLL_INITIALIZER(name) { \
99 .event = ATOMIC_INIT(0), \
100 .wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }
102 #define DEFINE_CTL_TABLE_POLL(name) \
103 struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name)
105 /* A sysctl table is an array of struct ctl_table: */
108 const char *procname
; /* Text ID for /proc/sys, or zero */
112 struct ctl_table
*child
; /* Deprecated */
113 proc_handler
*proc_handler
; /* Callback for text formatting */
114 struct ctl_table_poll
*poll
;
121 struct ctl_table_header
*header
;
124 /* struct ctl_table_header is used to maintain dynamic lists of
125 struct ctl_table trees. */
126 struct ctl_table_header
130 struct ctl_table
*ctl_table
;
137 struct completion
*unregistering
;
138 struct ctl_table
*ctl_table_arg
;
139 struct ctl_table_root
*root
;
140 struct ctl_table_set
*set
;
141 struct ctl_dir
*parent
;
142 struct ctl_node
*node
;
146 /* Header must be at the start of ctl_dir */
147 struct ctl_table_header header
;
151 struct ctl_table_set
{
152 int (*is_seen
)(struct ctl_table_set
*);
156 struct ctl_table_root
{
157 struct ctl_table_set default_set
;
158 struct ctl_table_set
*(*lookup
)(struct ctl_table_root
*root
,
159 struct nsproxy
*namespaces
);
160 int (*permissions
)(struct ctl_table_header
*head
, struct ctl_table
*table
);
163 /* struct ctl_path describes where in the hierarchy a table is added */
165 const char *procname
;
170 void proc_sys_poll_notify(struct ctl_table_poll
*poll
);
172 extern void setup_sysctl_set(struct ctl_table_set
*p
,
173 struct ctl_table_root
*root
,
174 int (*is_seen
)(struct ctl_table_set
*));
175 extern void retire_sysctl_set(struct ctl_table_set
*set
);
177 void register_sysctl_root(struct ctl_table_root
*root
);
178 struct ctl_table_header
*__register_sysctl_table(
179 struct ctl_table_set
*set
,
180 const char *path
, struct ctl_table
*table
);
181 struct ctl_table_header
*__register_sysctl_paths(
182 struct ctl_table_set
*set
,
183 const struct ctl_path
*path
, struct ctl_table
*table
);
184 struct ctl_table_header
*register_sysctl(const char *path
, struct ctl_table
*table
);
185 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
);
186 struct ctl_table_header
*register_sysctl_paths(const struct ctl_path
*path
,
187 struct ctl_table
*table
);
189 void unregister_sysctl_table(struct ctl_table_header
* table
);
191 extern int sysctl_init(void);
193 extern struct ctl_table sysctl_mount_point
[];
195 #else /* CONFIG_SYSCTL */
196 static inline struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
201 static inline struct ctl_table_header
*register_sysctl_paths(
202 const struct ctl_path
*path
, struct ctl_table
*table
)
207 static inline void unregister_sysctl_table(struct ctl_table_header
* table
)
211 static inline void setup_sysctl_set(struct ctl_table_set
*p
,
212 struct ctl_table_root
*root
,
213 int (*is_seen
)(struct ctl_table_set
*))
217 #endif /* CONFIG_SYSCTL */
219 int sysctl_max_threads(struct ctl_table
*table
, int write
,
220 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
222 #endif /* _LINUX_SYSCTL_H */