[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 <linux/uidgid.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_douintvec(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);
	void (*set_ownership)(struct ctl_table_header *head,
			      struct ctl_table *table,
			      kuid_t *uid, kgid_t *gid);
	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 <linux/uidgid.h>
	29	#include <uapi/linux/sysctl.h>
	30
	31	/* For the /proc/sys support */
	32	struct completion;
	33	struct ctl_table;
	34	struct nsproxy;
	35	struct ctl_table_root;
	36	struct ctl_table_header;
	37	struct ctl_dir;
	38
	39	typedef int proc_handler (struct ctl_table *ctl, int write,
	40	void __user buffer, size_t lenp, loff_t *ppos);
	41
	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_dointvec_jiffies(struct ctl_table *, int,
	51	void __user , size_t , loff_t *);
	52	extern int proc_dointvec_userhz_jiffies(struct ctl_table *, int,
	53	void __user , size_t , loff_t *);
	54	extern int proc_dointvec_ms_jiffies(struct ctl_table *, int,
	55	void __user , size_t , loff_t *);
	56	extern int proc_doulongvec_minmax(struct ctl_table *, int,
	57	void __user , size_t , loff_t *);
	58	extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int,
	59	void __user , size_t , loff_t *);
	60	extern int proc_do_large_bitmap(struct ctl_table *, int,
	61	void __user , size_t , loff_t *);
	62
	63	/*
	64	* Register a set of sysctl names by calling register_sysctl_table
	65	* with an initialised array of struct ctl_table's. An entry with
	66	* NULL procname terminates the table. table->de will be
	67	* set up by the registration and need not be initialised in advance.
	68	*
	69	* sysctl names can be mirrored automatically under /proc/sys. The
	70	* procname supplied controls /proc naming.
	71	*
	72	* The table's mode will be honoured both for sys_sysctl(2) and
	73	* proc-fs access.
	74	*
	75	* Leaf nodes in the sysctl tree will be represented by a single file
	76	* under /proc; non-leaf nodes will be represented by directories. A
	77	* null procname disables /proc mirroring at this node.
	78	*
	79	* sysctl(2) can automatically manage read and write requests through
	80	* the sysctl table. The data and maxlen fields of the ctl_table
	81	* struct enable minimal validation of the values being written to be
	82	* performed, and the mode field allows minimal authentication.
	83	*
	84	* There must be a proc_handler routine for any terminal nodes
	85	* mirrored under /proc/sys (non-terminals are handled by a built-in
	86	* directory handler). Several default handlers are available to
	87	* cover common cases.
	88	*/
	89
	90	/* Support for userspace poll() to watch for changes */
	91	struct ctl_table_poll {
	92	atomic_t event;
	93	wait_queue_head_t wait;
	94	};
	95
	96	static inline void proc_sys_poll_event(struct ctl_table_poll poll)
	97	{
	98	return (void *)(unsigned long)atomic_read(&poll->event);
	99	}
	100
	101	#define __CTL_TABLE_POLL_INITIALIZER(name) { \
	102	.event = ATOMIC_INIT(0), \
	103	.wait = __WAIT_QUEUE_HEAD_INITIALIZER(name.wait) }
	104
	105	#define DEFINE_CTL_TABLE_POLL(name) \
	106	struct ctl_table_poll name = __CTL_TABLE_POLL_INITIALIZER(name)
	107
	108	/* A sysctl table is an array of struct ctl_table: */
	109	struct ctl_table
	110	{
	111	const char procname; / Text ID for /proc/sys, or zero */
	112	void *data;
	113	int maxlen;
	114	umode_t mode;
	115	struct ctl_table child; / Deprecated */
	116	proc_handler proc_handler; / Callback for text formatting */
	117	struct ctl_table_poll *poll;
	118	void *extra1;
	119	void *extra2;
	120	};
	121
	122	struct ctl_node {
	123	struct rb_node node;
	124	struct ctl_table_header *header;
	125	};
	126
	127	/* struct ctl_table_header is used to maintain dynamic lists of
	128	struct ctl_table trees. */
	129	struct ctl_table_header
	130	{
	131	union {
	132	struct {
	133	struct ctl_table *ctl_table;
	134	int used;
	135	int count;
	136	int nreg;
	137	};
	138	struct rcu_head rcu;
	139	};
	140	struct completion *unregistering;
	141	struct ctl_table *ctl_table_arg;
	142	struct ctl_table_root *root;
	143	struct ctl_table_set *set;
	144	struct ctl_dir *parent;
	145	struct ctl_node *node;
	146	};
	147
	148	struct ctl_dir {
	149	/* Header must be at the start of ctl_dir */
	150	struct ctl_table_header header;
	151	struct rb_root root;
	152	};
	153
	154	struct ctl_table_set {
	155	int (is_seen)(struct ctl_table_set );
	156	struct ctl_dir dir;
	157	};
	158
	159	struct ctl_table_root {
	160	struct ctl_table_set default_set;
	161	struct ctl_table_set (lookup)(struct ctl_table_root *root,
	162	struct nsproxy *namespaces);
	163	void (set_ownership)(struct ctl_table_header head,
	164	struct ctl_table *table,
	165	kuid_t uid, kgid_t gid);
	166	int (permissions)(struct ctl_table_header head, struct ctl_table *table);
	167	};
	168
	169	/* struct ctl_path describes where in the hierarchy a table is added */
	170	struct ctl_path {
	171	const char *procname;
	172	};
	173
	174	#ifdef CONFIG_SYSCTL
	175
	176	void proc_sys_poll_notify(struct ctl_table_poll *poll);
	177
	178	extern void setup_sysctl_set(struct ctl_table_set *p,
	179	struct ctl_table_root *root,
	180	int (is_seen)(struct ctl_table_set ));
	181	extern void retire_sysctl_set(struct ctl_table_set *set);
	182
	183	void register_sysctl_root(struct ctl_table_root *root);
	184	struct ctl_table_header *__register_sysctl_table(
	185	struct ctl_table_set *set,
	186	const char path, struct ctl_table table);
	187	struct ctl_table_header *__register_sysctl_paths(
	188	struct ctl_table_set *set,
	189	const struct ctl_path path, struct ctl_table table);
	190	struct ctl_table_header register_sysctl(const char path, struct ctl_table *table);
	191	struct ctl_table_header register_sysctl_table(struct ctl_table table);
	192	struct ctl_table_header register_sysctl_paths(const struct ctl_path path,
	193	struct ctl_table *table);
	194
	195	void unregister_sysctl_table(struct ctl_table_header * table);
	196
	197	extern int sysctl_init(void);
	198
	199	extern struct ctl_table sysctl_mount_point[];
	200
	201	#else /* CONFIG_SYSCTL */
	202	static inline struct ctl_table_header register_sysctl_table(struct ctl_table table)
	203	{
	204	return NULL;
	205	}
	206
	207	static inline struct ctl_table_header *register_sysctl_paths(
	208	const struct ctl_path path, struct ctl_table table)
	209	{
	210	return NULL;
	211	}
	212
	213	static inline void unregister_sysctl_table(struct ctl_table_header * table)
	214	{
	215	}
	216
	217	static inline void setup_sysctl_set(struct ctl_table_set *p,
	218	struct ctl_table_root *root,
	219	int (is_seen)(struct ctl_table_set ))
	220	{
	221	}
	222
	223	#endif /* CONFIG_SYSCTL */
	224
	225	int sysctl_max_threads(struct ctl_table *table, int write,
	226	void __user buffer, size_t lenp, loff_t *ppos);
	227
	228	#endif /* _LINUX_SYSCTL_H */