[deliverable/linux.git] / include / linux / sysctl.h

/*
 * sysctl.h: General linux system control interface
 *
 * Begun 24 March 1995, Stephen Tweedie
 *
 ****************************************************************
 ****************************************************************
 **
 **  WARNING:
 **  The values in this file are exported to user space via 
 **  the sysctl() binary interface.  Do *NOT* change the
 **  numbering of any existing values here, and do not change
 **  any numbers within any one set of values.  If you have to
 **  redefine an existing interface, use a new number for it.
 **  The kernel will then return -ENOTDIR to any application using
 **  the old binary interface.
 **
 ****************************************************************
 ****************************************************************
 */
#ifndef _LINUX_SYSCTL_H
#define _LINUX_SYSCTL_H

#include <linux/list.h>
#include <linux/rcupdate.h>
#include <linux/wait.h>
#include <linux/rbtree.h>
#include <uapi/linux/sysctl.h>

/* For the /proc/sys support */
struct completion;
struct ctl_table;
struct nsproxy;
struct ctl_table_root;
struct ctl_table_header;
struct ctl_dir;

typedef int proc_handler (struct ctl_table *ctl, int write,
			  void __user *buffer, size_t *lenp, loff_t *ppos);

extern int proc_dostring(struct ctl_table *, int,
			 void __user *, size_t *, loff_t *);
extern int proc_dointvec(struct ctl_table *, int,
			 void __user *, size_t *, loff_t *);
extern int proc_dointvec_minmax(struct ctl_table *, int,
				void __user *, size_t *, loff_t *);
extern int proc_dointvec_jiffies(struct ctl_table *, int,
				 void __user *, size_t *, loff_t *);
extern int proc_dointvec_userhz_jiffies(struct ctl_table *, int,
					void __user *, size_t *, loff_t *);
extern int proc_dointvec_ms_jiffies(struct ctl_table *, int,
				    void __user *, size_t *, loff_t *);
extern int proc_doulongvec_minmax(struct ctl_table *, int,
				  void __user *, size_t *, loff_t *);
extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int,
				      void __user *, size_t *, loff_t *);
extern int proc_do_large_bitmap(struct ctl_table *, int,
				void __user *, size_t *, loff_t *);

/*
 * Register a set of sysctl names by calling register_sysctl_table
 * with an initialised array of struct ctl_table's.  An entry with 
 * NULL procname terminates the table.  table->de will be
 * set up by the registration and need not be initialised in advance.
 *
 * sysctl names can be mirrored automatically under /proc/sys.  The
 * procname supplied controls /proc naming.
 *
 * The table's mode will be honoured both for sys_sysctl(2) and
 * proc-fs access.
 *
 * Leaf nodes in the sysctl tree will be represented by a single file
 * under /proc; non-leaf nodes will be represented by directories.  A
 * null procname disables /proc mirroring at this node.
 *
 * sysctl(2) can automatically manage read and write requests through
 * the sysctl table.  The data and maxlen fields of the ctl_table
 * struct enable minimal validation of the values being written to be
 * performed, and the mode field allows minimal authentication.
 * 
 * There must be a proc_handler routine for any terminal nodes
 * mirrored under /proc/sys (non-terminals are handled by a built-in
 * directory handler).  Several default handlers are available to
 * cover common cases.
 */

/* Support for userspace poll() to watch for changes */
struct ctl_table_poll {
	atomic_t event;
	wait_queue_head_t wait;
};

static inline void *proc_sys_poll_event(struct ctl_table_poll *poll)
{
	return (void *)(unsigned long)atomic_read(&poll->event);
}

#define __CTL_TABLE_POLL_INITIALIZER(name) {				\
	.event = ATOMIC_INIT(0),					\
	.wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }

#define DEFINE_CTL_TABLE_POLL(name)					\
	struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name)

/* A sysctl table is an array of struct ctl_table: */
struct ctl_table 
{
	const char *procname;		/* Text ID for /proc/sys, or zero */
	void *data;
	int maxlen;
	umode_t mode;
	struct ctl_table *child;	/* Deprecated */
	proc_handler *proc_handler;	/* Callback for text formatting */
	struct ctl_table_poll *poll;
	void *extra1;
	void *extra2;
};

struct ctl_node {
	struct rb_node node;
	struct ctl_table_header *header;
};

/* struct ctl_table_header is used to maintain dynamic lists of
   struct ctl_table trees. */
struct ctl_table_header
{
	union {
		struct {
			struct ctl_table *ctl_table;
			int used;
			int count;
			int nreg;
		};
		struct rcu_head rcu;
	};
	struct completion *unregistering;
	struct ctl_table *ctl_table_arg;
	struct ctl_table_root *root;
	struct ctl_table_set *set;
	struct ctl_dir *parent;
	struct ctl_node *node;
};

struct ctl_dir {
	/* Header must be at the start of ctl_dir */
	struct ctl_table_header header;
	struct rb_root root;
};

struct ctl_table_set {
	int (*is_seen)(struct ctl_table_set *);
	struct ctl_dir dir;
};

struct ctl_table_root {
	struct ctl_table_set default_set;
	struct ctl_table_set *(*lookup)(struct ctl_table_root *root,
					   struct nsproxy *namespaces);
	int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
};

/* struct ctl_path describes where in the hierarchy a table is added */
struct ctl_path {
	const char *procname;
};

#ifdef CONFIG_SYSCTL

void proc_sys_poll_notify(struct ctl_table_poll *poll);

extern void setup_sysctl_set(struct ctl_table_set *p,
	struct ctl_table_root *root,
	int (*is_seen)(struct ctl_table_set *));
extern void retire_sysctl_set(struct ctl_table_set *set);

void register_sysctl_root(struct ctl_table_root *root);
struct ctl_table_header *__register_sysctl_table(
	struct ctl_table_set *set,
	const char *path, struct ctl_table *table);
struct ctl_table_header *__register_sysctl_paths(
	struct ctl_table_set *set,
	const struct ctl_path *path, struct ctl_table *table);
struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table);
struct ctl_table_header *register_sysctl_table(struct ctl_table * table);
struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
						struct ctl_table *table);

void unregister_sysctl_table(struct ctl_table_header * table);

extern int sysctl_init(void);

extern struct ctl_table sysctl_mount_point[];

#else /* CONFIG_SYSCTL */
static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
{
	return NULL;
}

static inline struct ctl_table_header *register_sysctl_paths(
			const struct ctl_path *path, struct ctl_table *table)
{
	return NULL;
}

static inline void unregister_sysctl_table(struct ctl_table_header * table)
{
}

static inline void setup_sysctl_set(struct ctl_table_set *p,
	struct ctl_table_root *root,
	int (*is_seen)(struct ctl_table_set *))
{
}

#endif /* CONFIG_SYSCTL */

int sysctl_max_threads(struct ctl_table *table, int write,
		       void __user *buffer, size_t *lenp, loff_t *ppos);

#endif /* _LINUX_SYSCTL_H */
Commit	Line	Data
	1	/*
	2	* sysctl.h: General linux system control interface
	3	*
	4	* Begun 24 March 1995, Stephen Tweedie
	5	*
	6	****************************************************************
	7	****************************************************************
	8	**
	9	** WARNING:
	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.
	17	**
	18	****************************************************************
	19	****************************************************************
	20	*/
	21	#ifndef _LINUX_SYSCTL_H
	22	#define _LINUX_SYSCTL_H
	23
	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>
	29
	30	/* For the /proc/sys support */
	31	struct completion;
	32	struct ctl_table;
	33	struct nsproxy;
	34	struct ctl_table_root;
	35	struct ctl_table_header;
	36	struct ctl_dir;
	37
	38	typedef int proc_handler (struct ctl_table *ctl, int write,
	39	void __user buffer, size_t lenp, loff_t *ppos);
	40
	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 *);
	59
	60	/*
	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.
	65	*
	66	* sysctl names can be mirrored automatically under /proc/sys. The
	67	* procname supplied controls /proc naming.
	68	*
	69	* The table's mode will be honoured both for sys_sysctl(2) and
	70	* proc-fs access.
	71	*
	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.
	75	*
	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.
	80	*
	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
	84	* cover common cases.
	85	*/
	86
	87	/* Support for userspace poll() to watch for changes */
	88	struct ctl_table_poll {
	89	atomic_t event;
	90	wait_queue_head_t wait;
	91	};
	92
	93	static inline void proc_sys_poll_event(struct ctl_table_poll poll)
	94	{
	95	return (void *)(unsigned long)atomic_read(&poll->event);
	96	}
	97
	98	#define __CTL_TABLE_POLL_INITIALIZER(name) { \
	99	.event = ATOMIC_INIT(0), \
	100	.wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }
	101
	102	#define DEFINE_CTL_TABLE_POLL(name) \
	103	struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name)
	104
	105	/* A sysctl table is an array of struct ctl_table: */
	106	struct ctl_table
	107	{
	108	const char procname; / Text ID for /proc/sys, or zero */
	109	void *data;
	110	int maxlen;
	111	umode_t mode;
	112	struct ctl_table child; / Deprecated */
	113	proc_handler proc_handler; / Callback for text formatting */
	114	struct ctl_table_poll *poll;
	115	void *extra1;
	116	void *extra2;
	117	};
	118
	119	struct ctl_node {
	120	struct rb_node node;
	121	struct ctl_table_header *header;
	122	};
	123
	124	/* struct ctl_table_header is used to maintain dynamic lists of
	125	struct ctl_table trees. */
	126	struct ctl_table_header
	127	{
	128	union {
	129	struct {
	130	struct ctl_table *ctl_table;
	131	int used;
	132	int count;
	133	int nreg;
	134	};
	135	struct rcu_head rcu;
	136	};
	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;
	143	};
	144
	145	struct ctl_dir {
	146	/* Header must be at the start of ctl_dir */
	147	struct ctl_table_header header;
	148	struct rb_root root;
	149	};
	150
	151	struct ctl_table_set {
	152	int (is_seen)(struct ctl_table_set );
	153	struct ctl_dir dir;
	154	};
	155
	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);
	161	};
	162
	163	/* struct ctl_path describes where in the hierarchy a table is added */
	164	struct ctl_path {
	165	const char *procname;
	166	};
	167
	168	#ifdef CONFIG_SYSCTL
	169
	170	void proc_sys_poll_notify(struct ctl_table_poll *poll);
	171
	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);
	176
	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);
	188
	189	void unregister_sysctl_table(struct ctl_table_header * table);
	190
	191	extern int sysctl_init(void);
	192
	193	extern struct ctl_table sysctl_mount_point[];
	194
	195	#else /* CONFIG_SYSCTL */
	196	static inline struct ctl_table_header register_sysctl_table(struct ctl_table table)
	197	{
	198	return NULL;
	199	}
	200
	201	static inline struct ctl_table_header *register_sysctl_paths(
	202	const struct ctl_path path, struct ctl_table table)
	203	{
	204	return NULL;
	205	}
	206
	207	static inline void unregister_sysctl_table(struct ctl_table_header * table)
	208	{
	209	}
	210
	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 ))
	214	{
	215	}
	216
	217	#endif /* CONFIG_SYSCTL */
	218
	219	int sysctl_max_threads(struct ctl_table *table, int write,
	220	void __user buffer, size_t lenp, loff_t *ppos);
	221
	222	#endif /* _LINUX_SYSCTL_H */